Author Topic: newmac combo furnace  (Read 8755 times)

Offline furnace woes

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newmac combo furnace
« on: December 30, 2008, 06:19:10 PM »
great site!

i have a newmac wb100 combination electric 20kw furnace(2004). i am having trouble with the dual thermostats working together. My electrician admits its his first one he ever installed, he searched the net for proper wiring,,,,,,,,,Big red flag for sure.
anyways there is a humming coming out of the power box on the wood section, i have got Newmac to send schematics but my electrician is refusing to fix what he says is 'normal'.
My hope is that someone else has had a Good electrican hook theirs up and can help me out. maybe a photo of their wiring or the name of an electrician who is Qualified.
Thanks for any time given,

Offline Admin

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Re: newmac combo furnace
« Reply #1 on: December 30, 2008, 06:52:02 PM »
This is a wood burning / electric forced air furnace?  I have no experience, but I assume it's just 24V that the thermostat sends back to the furnace to power the circulation fan and elements.

The buzzing noise is probably a 24V relay, maybe built inside a fan center.  If there was a wiring issue I would expect the transformer would have blown, so you're probably just dealing with a noisy relay.

As far as operational issues, I don't even know the seqeunce.  Electric furnaces are easy to troubleshoot.  It's the dual thermostat and wood burning part I havn't seen before.  There are no schematics onsite?  Behind the blower door of the furnace?  You said you have two thermostats?  Does one control the wood and the other control the electric, or are they both capable of controlling either wood / electric.  Sorry I can't be of more help.

I would recommend looking for a HVAC contractor with experience, he might be better suited to work on that appliance then an electrician, at least an electrician with no experience like me  :D

Offline rmuntz

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Re: newmac combo furnace
« Reply #2 on: January 03, 2009, 09:29:15 AM »
The 2 stats are both single stage heating stats. One controls the electric heat section. The other controls the combustion blower on the wood heating box- it cycles on and off to heat up the wood fire when calling and cool it down when not calling. The electric stat should be set a few degrees above the wood.