RECD Warranty Terms: Parts, Labour and Exclusions to Compare

Two RECD quotations land on your desk. Both say “12 months warranty.” One is ₹40,000 cheaper. On paper, they look identical. Six months after installation, the filter cartridge on the cheaper unit chokes, backpressure climbs, and the vendor’s service engineer points to a line on page four: “Filter elements are consumables and are not covered under warranty.” The replacement, plus two days of labour and a crane hire for your rooftop DG set, costs you more than the money you saved.

This is the most common way buyers get caught out with a Retrofit Emission Control Device (RECD). The warranty word is the same across quotes, but what sits underneath it, which parts, whose labour, which failures, how long, and from what date, varies enormously. This guide breaks an RECD warranty into its working parts so you can lay quotations side by side and compare what is actually being promised.

Quick Summary: What to Check in Any RECD Warranty

• Scope of parts: Is the filter media or cartridge covered, or only the outer housing?
• Labour: Does the vendor pay for removal, refitting, travel, lifting and access, or only supply a replacement part?
• Clock: Does the warranty start at dispatch, delivery or commissioning, and is it capped by running hours?
• Exclusions: Are engine-related exclusions specific and measurable, or vague enough to cover any failure?
• Response: How quickly will the vendor attend, and what happens to your compliance status while the unit is down?
• Conditions: What maintenance must you prove to keep the warranty valid?

Why an RECD Warranty Is Not Like a Generator Warranty

Most facility teams are used to DG set warranties from engine OEMs. Those warranties cover a machine whose performance depends mostly on its own design. An RECD is different because its health depends heavily on something it does not control: the engine upstream of it.

An RECD works by capturing particulate matter from the exhaust stream, and in many designs that captured soot is burnt off or cleaned out periodically. If the engine burns oil, runs rich, idles for long periods or uses poor-quality fuel, the device loads up faster. So every RECD vendor has an incentive to write exclusions that protect against bad engines, and every buyer has an incentive to make sure those exclusions do not swallow the whole warranty.

There is a second difference. A generator fault means no power. An RECD fault can mean no compliance. In the NCR, for example, the Commission for Air Quality Management (CAQM) has tied permitted DG operation in certain situations to sets being fitted with an RECD of the required particulate capture efficiency. A failed device during a GRAP period is not just a maintenance issue; it can affect whether you are allowed to run the set at all. Our guide on GRAP rules for DG sets in Delhi NCR explains how these restrictions work.

Finally, there is the relationship with your existing DG warranty. If your set is still under OEM cover, read whether installing an RECD affects the generator’s OEM warranty before you compare RECD terms. The two documents should not leave a gap where each side blames the other.

The Three Layers Inside Every RECD Warranty

It helps to think of an RECD warranty as three separate promises bundled together. Vendors often write them as a single paragraph, which is precisely why they are hard to compare.

Layer 1: Parts (Material and Manufacturing Defects)

This is the classic warranty promise: if a component fails because it was made badly, the vendor replaces it. The question is which components are in scope. An RECD system usually includes several distinct items:

• The outer shell or canister, usually stainless steel
• The filter element, substrate or cartridge that actually captures particulates
• Any catalyst coating on that substrate
• Inlet and outlet cones, flanges and gaskets
• Backpressure sensors, temperature sensors and pressure lines
• The controller, display or alarm panel, if fitted
• Regeneration hardware, such as heaters or burners, in active systems
• Mounting frames, supports, hangers and bellows supplied by the vendor

The single most valuable item on this list is the filter element. A warranty that covers the shell for five years but treats the element as a consumable may be worth very little in practice, because shells rarely fail. Ask every vendor to state, in writing, whether the element is covered against cracking, melting, delamination and plugging, and under what conditions.

Layer 2: Labour (Getting the Fix Done)

A replacement filter sitting in a carton at your gate does not restore compliance. Somebody has to shut down the set, remove the old unit, fit the new one, check for leaks and restart. On a basement DG room or a rooftop installation, that can involve scaffolding, chain blocks or a crane. Our articles on rooftop RECD installation and basement DG room access planning show how much effort access alone can take.

Labour cover is where quotations differ most. Look for clarity on:

• Engineer visit charges and travel or lodging for outstation sites
• Removal and reinstallation of the unit or element
• Lifting equipment, scaffolding and access platforms
• Exhaust pipe modification if the replacement differs dimensionally
• Freight for sending the faulty part back and the new part to site
• Post-repair testing, including backpressure checks

Layer 3: Performance (Does It Still Do the Job?)

A device can be mechanically intact and still not capture enough particulate matter. Performance cover asks whether the vendor stands behind the RECD’s capture efficiency and its backpressure behaviour during the warranty period. Many vendors keep this out of the warranty entirely and handle it through a separate performance guarantee tied to defined operating conditions. That is acceptable, as long as the guarantee exists and is linked to clear operating conditions. If neither document mentions performance, you only have a promise that the metal will not break.

Component-by-Component Comparison Sheet

Use a table like the one below when you have two or three offers in hand. Fill in each cell with exactly what the vendor wrote, not what you assume they meant. Where the quotation is silent, write “silent” and treat it as not covered until confirmed.

Item	Vendor A	Vendor B	Vendor C	What a buyer-friendly answer looks like
Outer housing / canister				Covered for full term against cracks, weld failure and distortion
Filter element / substrate				Covered against cracking, melting and abnormal plugging when engine is within agreed limits
Catalyst coating				Covered against premature deactivation with stated fuel specification
Sensors and pressure lines				Covered; replacement within a stated number of days
Controller / alarm panel				Covered, including firmware faults
Gaskets and fasteners				Supplied free during warranty service visits
Supports, bellows, frames				Covered if supplied by vendor
Engineer visits				Included for warranty faults, with a stated response time
Lifting and access				Clearly allocated, either included or quoted as a fixed rate
Freight both ways				Included

A lower quote that leaves five rows “silent” is often the more expensive option over three years.

When Does the Warranty Clock Start, and When Does It Stop?

A 12-month warranty can mean very different things depending on its start trigger. Common wordings include:

• From date of invoice or dispatch: The clock starts while the unit is still on a truck. If your site is not ready, you can lose months of cover before the device ever runs. This is a real risk if you order an RECD before your facility is ready.
• From date of commissioning: The clock starts when the RECD is installed and running. This is the fairest trigger for the buyer.
• “12 months from commissioning or 18 months from dispatch, whichever is earlier”: A common compromise. It protects the vendor from indefinite delays on your side while giving you reasonable cover. Check whether 18 months is realistic for your project schedule.

Then there is the end trigger. Some warranties run on calendar time, others on running hours, and some on both. For a standby set that runs a few hundred hours a year, a running-hour cap is rarely reached, so the calendar limit decides. For a prime power set in a factory running two shifts, an hour cap can expire long before the calendar date.

Usage pattern	Typical annual hours	Which limit usually bites first	What to negotiate
Standby set in an office or housing society	Low, often a few hundred	Calendar	Longer calendar term; hour cap matters little
Hospital or data centre with weekly testing	Low to moderate	Calendar	Cover for frequent cold starts and short runs
Factory with regular grid outages	Moderate to high	Running hours	Higher hour cap, or calendar-only warranty
Construction site or remote telecom site	High	Running hours	Clear hour figure; remote-site labour terms

If you are unsure how many hours your set actually runs, pull the hour meter readings and logbook first. Our guides on standby versus prime power and using DG load logs to assess RECD suitability will help you build a realistic usage profile before negotiating.

Exclusions: Where Most Warranty Value Disappears

Every warranty has exclusions, and most are reasonable. The goal is not to remove them but to make them precise. A good exclusion describes a measurable condition. A bad exclusion describes a feeling. Below are the exclusion families you will meet most often, with notes on what fair wording looks like.

Engine-Related Exclusions

This is the biggest category. Vendors will typically exclude damage caused by excessive lubricating oil carryover, coolant leakage into the exhaust, abnormal smoke, injector faults or turbocharger failure. All of these can genuinely destroy a filter element, so the exclusion is legitimate in principle.

The problem arises when the wording is open-ended, for example “any damage arising from engine condition.” That phrase can be used to reject almost any claim. Push for measurable triggers instead, such as:

• Lubricating oil consumption above a stated figure relative to fuel consumption
• Smoke opacity above an agreed value during a baseline test
• Backpressure upstream of the RECD outside the engine OEM’s permitted range
• Documented coolant or oil contamination found in the element on inspection

The best protection here is a recorded baseline. Before installation, have the engine’s condition documented: smoke check, oil consumption estimate, and backpressure reading. If your engine is borderline, consider whether you should complete an engine overhaul before fitting an RECD. Our article on engine oil consumption and RECD suitability explains why this one parameter matters so much.

Fuel Quality Exclusions

High-sulphur or contaminated diesel can poison catalyst coatings and increase ash loading. Vendors commonly exclude damage from fuel that does not meet the applicable specification. That is fair if the specification is named. It becomes unfair if the vendor can declare fuel “unsuitable” without testing it. Ask that any fuel-related rejection be backed by a fuel sample test from a recognised laboratory, ideally one accredited by NABL. For background on why sulphur content matters, see how ultra-low sulphur diesel improves emission control. If you run blends, also review biodiesel blends on an RECD-equipped generator and get the vendor’s position in writing.

Operation Outside Agreed Conditions

Vendors will exclude failures caused by running the set outside the conditions the RECD was designed for: prolonged very low load, extended idling, overload, or exhaust temperatures outside a stated band. This is reasonable only if those conditions were written down at the time of purchase. If the offer never mentioned a minimum load, the vendor cannot later claim your 20 percent load profile voids the warranty. Read our guides on choosing an RECD for a generator running at low load and RECD selection for frequent short start-stop cycles to understand which conditions you should disclose upfront.

Unauthorised Modification or Third-Party Work

Expect exclusions for damage caused when someone other than the vendor alters the exhaust line, relocates the RECD or opens sealed components. This is fair. Make sure, though, that routine work by your own maintenance team or your DG AMC contractor, such as checking sensor lines or cleaning a pre-filter as per the manual, is clearly listed as permitted. Otherwise, normal upkeep could be treated as tampering.

Wear Parts and Consumables

Gaskets, fasteners and some sensor seals are normal wear items. Vendors often list them as consumables. The line to watch is whether the main filter element is quietly placed in the consumables list. If the vendor genuinely expects the element to be replaced on a schedule, the schedule should be stated, along with the cost, so you can compare the lifecycle cost honestly. Our article on what a “maintenance-free” RECD claim actually means covers this from the sales-pitch side.

Environmental and Site Conditions

Corrosion in coastal locations, dust ingress at industrial sites and heat damage in poorly ventilated DG rooms are often excluded. If your site has one of these conditions, disclose it in your enquiry and ask the vendor to confirm the offered materials are suitable. Then the exclusion cannot be used against you later. See our guides on RECDs in coastal, salt-laden environments, dusty industrial locations and very hot ambient conditions.

Consequential Losses

Almost every vendor excludes indirect losses: lost production, penalties, sealing of the DG set or business interruption. You are unlikely to get this removed, and it is generally standard in equipment contracts. Under the Indian Contract Act, compensation for breach is in any case limited to losses that naturally arise or were reasonably foreseeable; you can read the Act itself on India Code. Instead of fighting this exclusion, negotiate faster response times and, for critical sites, a standby or loan unit arrangement.

Fair vs Overbroad: A Quick Reference

Exclusion topic	Overbroad wording to challenge	Fairer alternative
Engine condition	“Any failure attributable to engine condition”	Failure where measured oil consumption, smoke or upstream backpressure exceeds agreed limits
Fuel	“Use of inferior fuel”	Fuel proven by lab test not to meet the named specification
Load profile	“Improper operation”	Operation below or above load and temperature limits stated in the offer
Filter element	“Filter is a consumable”	Element covered for the term; scheduled replacement interval, if any, stated with price
Site conditions	“Adverse environment”	Conditions beyond those declared in the enquiry and accepted in the offer
Third-party work	“Any intervention by others”	Intervention beyond routine checks permitted in the O&M manual

Your Side of the Bargain: Conditions That Keep the Warranty Alive

Warranties are conditional. A vendor can reasonably expect you to operate and maintain the device properly. The fairness test is whether those obligations are written down, practical and achievable by your team. Typical conditions include:

1. Keeping a DG logbook with running hours, load and any abnormal events
2. Recording backpressure readings at stated intervals
3. Following the cleaning or regeneration schedule in the O&M manual
4. Maintaining the engine as per OEM schedule, with service records
5. Reporting alarms or high backpressure within a stated time
6. Allowing the vendor access for inspection

Ask for the O&M manual before you sign, not at handover. If the maintenance regime is heavier than your team can manage, factor in an AMC. Our RECD maintenance guide and the article on negotiating an AMC contract for your generator will help you decide.

One practical tip: create a simple shared log, even a spreadsheet, where your operator records hours and backpressure each week. In a warranty dispute, this log is usually the single document that decides the outcome.

Response Time and Remedy: What Happens After You Call

A warranty is only as useful as the vendor’s ability to act on it. Compare offers on these points:

• Acknowledgement time: How quickly will a complaint be logged and a ticket number issued?
• Attendance time: How many hours or days until an engineer reaches your site? Does this differ for metro, tier-2 and remote locations?
• Diagnosis rules: Who decides whether the fault is covered? Is there a joint inspection, and can you have your DG service provider present?
• Remedy hierarchy: Repair first, then replace, then refund? Who chooses?
• Turnaround for replacement parts: Are spare elements stocked in India, or imported to order?
• Bypass arrangement: If the element must be removed for repair, will the vendor provide a temporary spool piece, and what are the compliance implications of running without it?

For sites where downtime is not an option, such as hospitals and data centres, negotiate a tighter response time and, if possible, a spare element held at site or at the nearest service centre.

Compliance Documents and the Warranty

An RECD’s legal value comes from its certification. Under CPCB’s system for testing retrofit emission control devices, certified products are subject to periodic Conformity of Production checks, and your installation relies on the product’s approval being valid. You can find official notices and lists on the Central Pollution Control Board website, and testing agencies such as ICAT and ARAI are involved in type approval.

Two warranty-adjacent questions are worth putting to every vendor:

1. If a warranty replacement element or unit is supplied, will it be the same certified model, and will the vendor provide updated documentation for your records?
2. If the vendor’s certification for your model lapses during your warranty period, what is their obligation to you?

Our guides on how to verify a CPCB-tested RECD and how to read an RECD test certificate explain what to look for in these documents.

Transferability and Change of Ownership

Facilities change. You may sell the DG set, move it to another site, or hand over a building to a new RWA committee. Check whether the warranty is tied to the original buyer, the site address or the device serial number. If you might relocate the device, read whether an RECD can be transferred to another diesel generator, because moving the unit to a different engine raises both technical and warranty questions. Rental sets have their own complications, covered in our article on installing an RECD on a rented diesel generator.

Extended Warranty and AMC: Are They Worth It?

Many vendors offer an extended warranty or a comprehensive AMC after the standard period. Evaluate it as you would an insurance product:

• Does the extension cover the filter element, or only the housing and sensors?
• Are scheduled cleanings or regenerations included in the price?
• Is labour included, and are there visit limits?
• Is the price fixed, or subject to annual escalation?

Compare the cost of the extension with the vendor’s own stated price for a replacement element plus labour. If one element replacement over the extended period would cost more than the AMC, the AMC is probably good value. If the AMC price is close to the full device cost, you are likely paying for visits you do not need. Our article on in-house maintenance versus AMC for generators gives a broader framework, and RECD cost in India helps you benchmark replacement costs.

A Weighted Scorecard for Comparing Offers

Price comparison alone rewards vague warranties. A simple weighted scorecard helps you reward clarity instead. Adjust weights to suit your site.

Criterion	Suggested weight	Score 1 (weak)	Score 5 (strong)
Filter element coverage	25%	Excluded as consumable	Covered for full term with clear conditions
Labour and access	20%	Part supply only	All labour, travel and access included
Start trigger and term	15%	From invoice, short term	From commissioning, longer term
Exclusion precision	15%	Vague, open-ended	Measurable thresholds
Response time	15%	Not stated	Stated, with escalation path
Documentation and certification support	10%	Not addressed	Replacement documents and COP status committed

Multiply each score by its weight, sum them, and then put the total next to price. This gives your committee or management a defensible basis for choosing an offer that is not the cheapest.

Questions to Send Every Vendor Before You Decide

1. Is the filter element or substrate covered under warranty? For how long, and against which failure modes?
2. Does the warranty include labour, travel, freight and lifting for warranty repairs?
3. From which date does the warranty start, and is there a running-hour cap?
4. Which engine parameters will you use to decide whether a failure is engine-related, and what are the limits?
5. Will you conduct and record a baseline engine and exhaust check before installation?
6. What is your attendance time for our location, and where is your nearest service base?
7. Do you stock replacement elements in India? What is the typical lead time?
8. What maintenance must we perform to keep the warranty valid? Please share the O&M manual.
9. Can our DG AMC contractor carry out routine checks without voiding the warranty?
10. Is the warranty transferable if the building or the DG set changes ownership?
11. What happens to warranty obligations if your certification for this model lapses?
12. What are the price and scope of an extended warranty or AMC after year one?

Ask for answers in writing, and attach them to the purchase order. Our guide on reviewing deviations in an RECD technical offer shows how to log these answers alongside other offer gaps. A friendly verbal assurance from a sales engineer carries no weight in a dispute twelve months later. When you are shortlisting suppliers, our guide on choosing CPCB-approved RECD vendors complements this checklist.

Sample Warranty Clause Language You Can Adapt

The wording below is a starting point for discussion with your vendor and your legal or procurement team. It is not legal advice, and you should adapt it to your contract format.

“The Supplier warrants the Retrofit Emission Control Device, including the housing, filter element, catalyst coating, sensors, controller and Supplier-supplied supports, against defects in design, materials and workmanship for a period of [__] months from the date of successful commissioning, or [__] months from the date of delivery to site, whichever is earlier. During this period, the Supplier shall, at its own cost, repair or replace any defective component, including all labour, travel, freight and access equipment reasonably required. Exclusions relating to engine condition shall apply only where measured parameters recorded in the commissioning report are exceeded, namely lubricating oil consumption above [__], smoke opacity above [__] and upstream exhaust backpressure above [__]. The Supplier shall attend site within [__] hours of a written complaint.”

Frequently Asked Questions

Is the RECD filter usually covered under warranty?

It depends on the vendor. Some cover the filter element for the full warranty term against defects and abnormal failure. Others classify it as a consumable. Always ask for this in writing because it is the most expensive single component to replace.

Does an RECD warranty cover the cost of removing and refitting the unit?

Not automatically. Many offers cover only the replacement part. Check whether labour, travel, freight, scaffolding and lifting are included, especially for rooftop or basement installations.

Can a vendor reject a claim by blaming my engine?

Engine-related exclusions are normal, but they should be tied to measurable parameters. Recording a baseline at installation and maintaining engine service records is your best protection.

Should the warranty start from invoice date or commissioning date?

From commissioning is fairer for the buyer, often with an outer limit measured from delivery. Starting from invoice date can consume your cover before the device runs.

Does a longer warranty mean a better RECD?

Not necessarily. A five-year warranty that excludes the filter element can be weaker than a one-year warranty that covers everything including labour. Compare the scope, not just the duration.

Bringing It Together

An RECD warranty is really three promises: the parts will not fail, someone will fix them if they do, and the device will keep doing its job. Comparing quotations means separating these promises, checking the start and end of the clock, and replacing vague exclusions with measurable ones. Do that, and the “same” 12-month warranty on two quotes will start to look very different, usually in a way that makes your decision easier.

If you would like a clear, itemised warranty statement for your DG set, explore our CPCB-certified Retrofit Emission Control Devices or contact the Aceget team with your DG nameplate details. Our guide on which nameplate photos to share for an RECD enquiry will help you get an accurate offer the first time.