I have a honeywell hot water tank installed in 2011. It has a thermopile which I cleaned tested with a voltmeter and is working (rise to 685 mV in 3 minutes. When I light the pilot light by holding button down it lights great ands stays lit working perfectly and even if I hold it down for 2 minutes goes out as soon as I release the button.

Ideas? Model #MI5036FBN, WV8840A1000 control valve.

I took it apart and have not assembled it precisely yet. A little gas is getting out and could trip a gas sensing switch?

I tested the thermal cutoff switch and

Change the thermocouple anyway - and be sure the pilot flame comfortably reaches the tip of the thermocouple.

I had this problem once and flame still wouldn't stay lit.

I am not giving you advice to blow yourself up working with gas and an open flame. I assume anyone who will attempt to test their water heater that it will be PAST the warranty period. Otherwise you will void any warranty left on parts replacement.

Seven blinks means "Gas Control electronic fault detected".

Probable Cause:

1. Control needs to be reset.

2. Control is wet or physically damaged.

Service Procedure:

1. Reset the control

2. Replace Gas Control

A new gas control valve on Amazon is only $139-$159.

I tried resets turning to pilot then very hot, 10 seconds, then hot 10 seconds, that did not work. It did start giving me a slid green LED sometimes when I light pilot and pilot goes off when I release.

Very Hot 10 Seconds

Then Hot 10 Seconds.

And Pilot for 10 Seconds.

Then turn it to A .

Never go past A or B, this causes the thermostat / Control value to fail.

What I do to all my gas water heater is do away with their crummy drain valve that is so limited on flow, you'll never remove the larger sediment.

I install a 3/4" Full Port Ball Valve designed for water heater drains.

On an 11 year old water heater the anode is shot and the glass lining could be all eaten thru. I would drain the tank by removing the hose drain valve and install a 3/4" x 6" nipple and short hose into a bucket to catch the sediment. After it's drained of water, I'd look inside the water heater thru the drain valve port, removing the nipple. With a small flashlight I'd examine the anode, walls of the water heater and floor. If there is too much rust, I'd get a new water heater.. Especially if the water heater is in the basement or inside the structure it could leak a cause a flood. Better safe then sorry.

For a client with a water heater in the house inside a closet: I put the water heater on blocks with a pan right under the water heater. I was able to run a 3/4" drain pipe thru the wall to the exterior. If the T&P valve opened or if the water heater started to leak, the water would drain outside.

I often get a valve and burner assembly from tree bay, not new but functional - sometimes you have to wiggle and juggle.

Never turn a modern tanked water heater above HOT (A or B). Therefor for rentals you may have to provide a larger tanked water heater.

A 30 gallon for 1 person or maybe 2.

A 40 gallon for 2 to 3 people

And a 50 gallon for 4 or more people.

Also you can get a higher recovery unit.

Instead of a 30,000 BTU to a 38,000 BTU

Instead of a 35,000 maybe a 42,000

And instead of a 40,000 a 50,000 BTU unit.