Possibly stuck gas valve

ScottE10

Coleman GF8100G16MU11B

Hello, thinking I might have a stuck gas valve. Is there anyway to be sure that is the case?

Inducer motor starts, igniter starts to glow.. after a few seconds I hear a click from the mother board telling me it's time for the gas to start flowing, but nothing happens..

I tapped on the gas valve a few days ago and it came on, ran for a few days then stopped.

Tried tapping again and I get nothing. I checked to see if I am getting power to the gas valve and I do. I believe I should also hear or feel a click when the gas valve turns on, but I don't feel or hear anything…

Is there anything else I can check to make sure it is the gas valve before I go and buy a new one?

Thanks!

Scott

mattmia2

It is possible but much more likely the solder joints have failed somewhere on the control board and your tapping is making them make contact.

ScottE10

well, I do get power coming to the gas valve from the control board… But I will check those connections…

Thanks!

ScottE10

Well MattMia2, you were absolutely correct! I went out just a little bit ago to see if I could see anything behind the control board. Nothing was noticeable, so I put things back together, started up the furnace, waited for the click to know it was time for the gas to come on.. Nothing.. So on the 2nd cycle I started wiggling the set of 12 wires right at the control board and the gas came on.. I stopped,let go and the gas went off.. So I checked every wire, but I couldn't tell which one it could be, so I just pushed every wire to make sure they were all on good and also reseated the connector… This time the gas stayed on.. I put some ties on it to keep the wires pulled up instead of them being pulled down like they seemed to be… So far the gas has stayed on..

So I want to thank you very much!! I hadn't even thought that a wire might have been coming loose on the control board… You literally saved me a ton of money!!

I am forever grateful!!

Scott

mattmia2

unless the connector was obviously not seated all the way you have probably just found the symptom, not the problem. where one of those pins is soldered to the board is probably broken

109A_5

Hello ScottE10'

" I checked to see if I am getting power to the gas valve and I do. "

How did you actually measure this ? Both meter probes at the wire connections on the gas valve or one probe grounded somewhere ?

Poor solder connections at relays and connectors is very common.

ScottE10

@mattmia2 I'm hoping it just needed reseating… But if it stops again I will look more into seeing if a pin is broken..

@109A-5 - I tested it at the wire connections on the gas valve..

Thanks!

Scott

EBEBRATT-Ed

The connection may have been good enough to get a meter reading but failed under the gas valve load.

Sometimes just unplugging and plugging in a plug is the fix.

PC7060

this example is typical of the conditions @mattmia2 described.

Jamie Hall

A faulty solder joint is common enough — but a pin which isn't tight enough in its socket is another common one, or even a pin which isn't properly crimped…

109A_5

https://forum.heatinghelp.com/discussion/comment/1827111#Comment_1827111

Yes, a classic example, sadly very common in most all electronic equipment, often an easy inexpensive repair if you can solder.

Best practice is to add new solder, then remove the majority of the solder (old and new) from the joint then re-solder making a nice new joint, then remove the flux.

In some cases scraping away some of the solder mask (over the copper foil) and adding an appropriately sized wire bridging the gap between the component lead and the copper foil will make a connection that will last a lot longer. Securely encircle the component lead with the added wire and re-solder.

With a relay or a multi circuit connector re-solder all the related joints.

mattmia2

https://forum.heatinghelp.com/discussion/comment/1827122#Comment_1827122

glue the relay in place with some silicone or hot melt glue too. the vibration from the relay fatigues and cracks the solder. if it has some mechanical support it usually won't crack again

109A_5

https://forum.heatinghelp.com/discussion/comment/1827126#Comment_1827126

As much as that will probably work, depending on the situation, I don't like gluing things down (unless the OEM did it). When the day comes that the device actually needs replacement (relays fail) it becomes a PITA to remove the device and if not careful with the removal the surrounding components can be damaged. If you can glue across the top of multiple components that often helps with vibration dampening and aiding to the mechanical integrity and is much easier to remove a single defective component. To me, very situational dependent, to glue or not.

mattmia2

It is not difficult at all to pry the glue off with a small screwdriver to remove the part or melt it if it is hot melt glue. generally you will never have to touch it again after you've fixed the mechanical deficiency.