Atwood Hydro Flame MODEL 8535- III No heat

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New member
Nov 9, 2012
Hello, I have a 95 Fleetwood Prowler, with an Atwood Hydro Flame Furnace model 8535III.  I do not have power to the DSI board.  I have installed a new one and a new relay.  Still the blower blows but no heat.  I have bought a new sail switch, but have not installed it.  Is there any tips or other parts it could be.  We travel for work with 3 kids and the furnace is down.  We are heating with portables.  Any suggests will be very much appreciated.  Thank you so much!

John From Detroit

Well-known member
Apr 12, 2005
Davison Michigan
Rather than throwing money at it straight off, normally I would say "I would" but in this case I have to say "I" without the "would" cause Well.. Been there. not exactly the same symptoms.

The "DSI board" as you call it, is the master control board if I'm not mistkaen on that model.  A dinosaur.  Mounted to the left of the motor as you look at it from outside.

It is the ONLY board.

You said the blower blows.

What I did was download the service manual, From this I was able to identify all the assorted leads and pins on the plugs, and then I was able to test the sail switch (Yes it was good) and the high temp cut-off) likewise) and some other things by watching for voltage.

In my case the furnae DID light, but almost immed shut off.

I checked the burner, the flame sensor and a everythign else I could find, and finally I admitted:

I had to replace the control board.

Attwood, I got a quote from a local dealer of "Around 250" on-line searches said he's very fair (Roughly the same price)

Dionsaur board Fan fifty, 108 delivered

Better board

But I would recommend you do as I did, eliminate everything else before throwing more money at it.
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