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Intertherm Gas Valve

Posted: Thu Sep 25, 2008 12:34 am
by Bad Dad
Hi all, I have an Intertherm Furnace Model No. MGHA-070ABFC-02
I tried to fire it up for the pre winter check but found the pilot light
was out and would not light. Replaced the thermocouple and pilot now works, but I have to furnace flame. I checked the transformer
with volt meter. Have 28 volts. Checked the gas valve for ohms,
could not get a reading. Checked gas valve for voltage and have
26 volts. Would you suspect that the gas valve is bad?
Also, are the gas valves on these furnaces solenoid operated?
If so, can I just replace the solenoid?
What are your thoughts on no Flame?
One other thing, central air conditioning was added to this unit
later. How much later I do not know as it was installed before I
bought the home.
Any help at all would be great.
Thanks.......

RE: Intertherm Gas Valve

Posted: Fri Sep 26, 2008 1:20 am
by Robert
Hi,

Check the burner and burner orifice for clogs/spider webs/etc. . make sure all is clear and then see if gas is flowing.


IF gas valve is not opening properly, it cannot be repaired and must be replaced.


IF it is getting power and it is, it should open, if not it is bad.



Thanks,
Robert

RE: Intertherm Gas Valve

Posted: Thu Oct 02, 2008 11:26 pm
by Bad Dad
Thanks for the reply Robert.
I checked everything and replaced the Gas Valve.
I still do not have any flame from the burner.
Where do you suggest I look now?
I need all the help I can get........
This may not make a difference but I failed to tell you that
this furnace is burning propane, not natural gas...

RE: Intertherm Gas Valve

Posted: Fri Oct 03, 2008 12:15 am
by Robert
Hi,

Did you convert the new gas valve for use with LP, most if not all come set for Nat. Gas.


Next would be to have the input and manifold gas pressures checked for proper pressure.



Take care and best wishes,
Robert

RE: Intertherm Gas Valve

Posted: Fri Oct 03, 2008 12:53 am
by Bad Dad
I replaced the gas valve with an identical new valve. My thoughts
are that it is set for both natural and propane gases. The sticker
on the new valve shows Nat. 3.3", LP 10.0"

Of course you probably have figured that I am trying to avoid the
costly repair man. So how does one check the input and manifold
gas pressures? And lets assume they are okay, where would I
got from there?
Isn't this fun.......

RE: Intertherm Gas Valve

Posted: Fri Oct 03, 2008 2:48 am
by Robert
Hi,

The gas valve can be used with nat. gas and lp, BUT it comes set for nat. gas and must be converted for use with lp.


Checking gas pressures requires special tools and gauges plus experience in that type of work.


I know you want to avoid a repair bill, but sometimes it is not safe to try to DIY.

This is one of those times.

Making a misdiagnosis or error on a gas furnace using LP can be extremely dangerous.


Take care and best wishes,
Robert