# HHT part 4021-229B rev C



## Nh880 (Dec 8, 2018)

A nearby lightning strike too out bunch of electronics. Fireplace fan wont turn on. I bypassed the fan plug and it runs direct from wall but won't turn on with the fireplace. Seems that the control switch is bad as the test button wont work either.
I have 4021-229-B Rev C control but unable to find it anywhere online. Is there a new part number as replacement for it? Will it be the 708 model?

Appreciate some help.


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## DAKSY (Dec 9, 2018)

What model fireplace do you have?


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## Nh880 (Dec 10, 2018)

Its NDV4236I


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## DAKSY (Dec 10, 2018)

https://www.amazon.com/dp/B01N6DAJHN/?tag=hearthamazon-20


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## Nh880 (Dec 10, 2018)

DAKSY said:


> What model fireplace do you have?


Its NDV4236I


DAKSY said:


> https://www.amazon.com/dp/B01N6DAJHN/?tag=hearthamazon-20


Thanks. This one has less wires vs the 229B model currently in. Am I to assume that the 2 wires will just go in the power strip to control fan and leave the rest out? How will it turn on/off with the temperature?
Any thoughts on the 708 model if that will work or no?


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## DAKSY (Dec 10, 2018)

Normally, one leg from the rheostat goes to the junction box under the unit. The other leg goes to the snap (aka Thermo) disk.
Coming out of the snap disk is a wire into the blower & coming out of the blower is a wire that completes 
the circuit by being plugged into the Junction box. The snap disk actuates the system when the unit body
reaches a designated temperature & opens the circuit when the unit cools. Without seeing the wiring schematic
from your install manual, I would guess your is probably wired the same as what I described...


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## Nh880 (Dec 10, 2018)

There are 3 wires (black, red and white) that go from the fan control in to the power strip for the fan.

There are two black wires that come out from the other end of the control switch. One wire is grounded and second goes into the main and into the fireplace.


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## DAKSY (Dec 10, 2018)

Isn't there a green ground wire coming off the blower body?


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## Nh880 (Dec 10, 2018)

Yes. The green wire from the blower body is there. See picture.


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## Nh880 (Dec 10, 2018)

Here is a better picture.


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## DAKSY (Dec 10, 2018)

If the blower is grounded, I think the wire from the rheostat is redundant.
I see no issue with replacing your rheostat with the two-wire version.


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## Nh880 (Dec 10, 2018)

DAKSY said:


> If the blower is grounded, I think the wire from the rheostat is redundant.
> I see no issue with replacing your rheostat with the two-wire version.


let me try it I guess. 

So one wire will go to the power strip to control the fan and other one with the main wire which is the green one in the picture.


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## DAKSY (Dec 10, 2018)

Do you have the install instructions for the blower assembly?
You should. The blower is an OPTION for this unit & does not
come the factory with one in the unit.
That's where the wiring schematic is.


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