pilot wont stay lite reliance 606 water heater

[billy0510]

a few weeks ago we had this problem start in which our gas water heaters pilot light would go out at times.  I cleaned the little air vent and lite the pilot it would stay on for a few hours and then go out again. this happened for a day and a half and then it started to work fine.  Now its back :yikes:its done it two times 4times today i just lite it again about ten minutes ago. I tried lighting it and letting the therm. turn it off several of times and it stayed lite.  But in a few hours it will probably be out again.

[hvacdrd]

Do you have a full model number(located on the ID tag) and approximate age of the water heater? Is access to the burner sealed or does it have a removable cover (one that is not screwed in place)

If this is a newer style with FVIR(flame vapor ignition resistant) take a look at this technical bulletin to see how this works and then follow these cleaning instructions. The problem is usually a lack of combustion air or poor draft.

[Budget Appliance Repair]

If this is a relatively newer waterheater, (like within the last 4 years old), then you most likely have the newer sealed burner chamber style.

Here's an excert(sp?) from the manual:

FLAMMABLE VAPOR IGNITION RESISTANT DESIGN

This section will address the changes brought about by the introduction of FVIR compliant products. Other

than items mentioned here, the construction, installation, and service will remain the same as discussed in

the primary handbook.

The FVIR acronym stands for "Flammable Vapor Ignition Resistant." The AO Smith products are based on

"Corderite Combustion Containment" known as “C3 Technology™” . The C3 Technology design features a

sealed (from non designated air intake openings) combustion chamber and a "flame arrestor" component.

This class of residential gas water heaters meet the new ANSI standards and testing protocols (ANSI

Z21.10.1) established to deal with the accidental or unintended ignition of flammable vapors, such as those

emitted by gasoline. Virtually all gas-fired, atmospherically vented, residential water heaters manufactured

in the United States with BTU ratings of 75,000 or less are required to meet this new ANSI standard

effective July 1,2003. The current implementation schedule for C3 TECHNOLOGY compliant residential

gas-fired products is shown in the following table. These dates are subject to change.

A.O. Smith Water Products Company Technical Training Department ©2005 Ashland City, TN Page 15

This is a now new required design for safety to keep from igniting flammable vapors that may come in contact with the waterheater, (such as leaving a fuel container or greasey rags piled around the waterheater).

These units have a material, (Corderite), on the bottom where the fresh air enters and any flammable vapors would enter. In the case of flammable vapors igniting in the burner chamber the flames can't go back out thru the bottom because of the Corderite flame arrestor.

Recently I've been seeing a bunch of these just at the 2-4 years old point starting to plug up with dust and not letting enough air in for the burner to operate correctly.

As part of the safety the thermocouple assembly has a TCO, (Thermal cut-out), in it's circuit so that if a flammable vapor ignites in the heat chamber or if not enough air is entering to burn correctly the burner chamber will be hotter then when operating correctly and the pilot will be shutoff shutting the complete system down so as to not continue burning the flammable vapors or cause a carbon monoxide problem from the burner not burning with enough air. The TCO is a resetable device, it resets when the temp goes back down below a preset level. That is why you can relite it again after you have noticed that the you don't have hot water.

To clean these so they work properly again you will have to carefully remove the complete burner assembly. Then you will see a metal plate that is under the burner/pilot assembly. This plate has to be lifted up and proped up so as you can get a compressed air can or air gun inside and blow and debrie back down and out of the Corderite flame arrestor. I purchased a computer/electronic cleaning vacuum attachment from Harbor Frieght to be able to get into and under the flame arrestor vacuuming from the bottom air inlet openings while blowing down from the top.

Make sure the black plastic screen is cleaned good also and correctly installed back in place over the air inlet opening at the base of the waterheater. Keep the area around the waterheater cleaned and vacuumed on a regular bases also to keep as much dust and lint away as possible.

Here's a good service handbook that explains the operation and repair of these units, Service Handbook for Residential Gas & Electric Water Heaters CLICK HERE to download service & repair manual. Start reading at Page 15.