ELX Flue Grommet Upgrade

We at HTP have discovered a potential issue with a Grommet Seal in the select HTP Elite XL Commercial high efficiency condensing boilers and volume water heaters.

Specifically, a Grommet Seal affixed to the flue discharge pipe and temperature probe inside the product can degrade and crack as a result of prolonged exposure to corrosive flue gases. For the safe and efficient operation of the boilers, we have decided to issue an Important Safety Upgrade, whereby the Grommet Seal on all affected products will be replaced with a new Grommet Seal from a different material.

Affected Models:



























Affected Serial Number Range:

Current Format: from 3253093U4212980000054 to 3253008U4230820000097 (after 10/20/21 production date)
Legacy Format: from 082418B1041203 to 101921B1041040 (before 10/20/2021 production date)

NOTE: Boiler Build Dates can be decoded per the following examples.

1. Current Format-3253008U4230820000097
3253008 = SAP CODE for that Model boiler
U4 = Freetown Plant
23082 = Year 2023 (First two digits), Day #82 of that year (Next three digits)
97th product built on that day (Final seven digits)

2. Legacy Format-082418B1041203
082418 = MMDDYY
August 24,2018


The Grommet Seal in question can be found inside the affected boilers (see Before picture) and the upgrade requires installation of a band to secure the grommet (see After picture).




HTP has developed an upgrade kit designed to be field-installed that includes a new replacement Grommet Seal and an additional retaining system (metal band).

Immediate Action for Contractors


1. The Upgrade Kits contain all the necessary materials to completely and safely upgrade the ELX boiler.
There are 3 different kits to accommodate different sized boilers and volume water heaters:

Upgrade Kit # 64980811: this kit has a 4” metal band and it is designed to retrofit boilers and volume water heaters from 400 to 500 MBH
Upgrade Kit # 64980812: this kit has a 6” metal band and it is designed to retrofit boilers and volume water heaters from 650 to 1000 MBH
Upgrade Kit # 64980813: this kit has an 8” metal band and it is designed to retrofit boilers and volume water heaters from 1500 to 2000 MBH

2. If you require any additional kits, click on the Upgrade Kit # above, and you will be directed to our Online Parts Store.

3. If you have any questions, please contact HTP via email at warrantysupport@aristonthermo.us, or by phone at 1-800-323-9651 option 1 (HTP) then option 3 (Warranty).

4. If you are an Installer and have made HTP ELX Grommet Seal Upgrades, please use the button below to record your upgrade and apply for reimbursement.

5. Reimbursement will be provided on a sliding scale. The first boiler per site will result in a $150 reimbursement. Each additional boiler at a particular site will result in an additional $50 (up to a maximum of 8 boilers per site). This can result in a maximum reimbursement per site of $500!

6. Instructions on how to complete the reimbursement form can be found here

Apply for Reimbursement

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