Tip & How-To about Heating & Cooling

How to fix your gas furnice

Most gas furneses have a red light on circuit board wich is located on intake. turn heater off then have someone turn it back on while you watch the circuit board. count the # of times the red light flashes before it pauses. it will flash in a cycle. for instance it flashe 3 times then pauses for 5 secounds then flashes 3 times again on and on. look on the back of the panel cover,their will be a diagram, in the diagram their will be dianostic report that will include what that # of flashing red light and what it means. for examle 3 flashing red lights ps stuck open. that means pressure switch stuck open. replace the part and your back up and running.

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MasterTemp 400K BTU heater kicks on for 20sec. and starts shaking, then turns off and repeat itself. Everytime it kicks on we smell gas as well. Water flow seems to be OK in spa and pool.

Even though you are smelling gas it could mean the gas flow is not strong enough.
When you say the water flow seems good, have you cleaned your filter recently?

If you are somewhat handy you can troubleshoot this heater by taking off the front panel turning it on and looking up to the back of the circuit board.
When it shuts off it will have red lights next to abbreviated words such as hl1 hl2.

Whichever light or lights are red will point you in the right direction of the cause.

Mar 27, 2017 | Pool & Spa

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I have a model 6G40PVW-40F water heater and we have no hot water... the thermostat light on warm/vacation is on and so are 2 other lights...If I diconnect it and re-connect it then it will start..the gas turns on and the burner turns on but the flame will only be on about 10 seconds and will turn off and the three lights light up again...what can this be???

Most gas water heater problems today can be solved with yearly maintenance that includes cleaning burner parts, clean air intake, check venting, check electrical connections, bleed gas line, and check gas pressure.
Gas water heater manuals recommend yearly maintenance by service technician.

In past years, gas water heaters required less maintenance, but they were less energy efficient and more dangerous to operate.

Sounds like you have Intellivent gas control valve thermostat.
Open following link to identify gas valve and see error codes:

Error light on vacation + 2 other lights = 3 possible conditions:
1) Wiring error: check outlet with circuit analyzer:
2) Pressure switch tubing not connected, air intake obstructed (clean intake), or vent exhaust obstructed (check for proper venting).
3) System in lockout: Low gas pressure, hot surface igniter not positioned correctly.

You can do some of this yourself.

Jun 30, 2011 | Rheem 40 GAL ELEC TALL Water Heater 6YR SC...

1 Answer

goodman furnace model # GMNT100-4B On vacation, neighbor checked house, house filled with gas. He shut off main and furnace. came home turned on gas to everything except furnace. All good. Furnace will not light. The indicator light is solid red. Any suggestions on next troubleshooting step. Thanks.

Solid red typically means bad controller. Try unplugging the furnace, wait about 30 secs, then plug it back in. The possibility that the controller was sending voltage to the valve even when there was no flame is a bad sign. If the controller starts the furnace, watch it very closely and see what it does. If the solid light comes back on, it's time for a new board.

Mar 24, 2010 | Goodman GMS90703BXA Heater

1 Answer

gas heater circuit board

On the bottom door where the blower foor is located,
look on the back of it. It should have a Electrical print
and at the very bottom A Troubleshooting chart for
the control board. It is hard to find but it is on there.

Usually a solid Red means system is ready and good
to go.

Good luck, if you need anymore help let me know.

Feb 14, 2010 | Heating & Cooling

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