Hot Dawg Heater Troubleshooting

[Draven8795]

Anyone have a good link to a trouble shooting guide or want to walk me through a test?

My hot dawg heater fires up and runs but the main fan won't kick on. I'm thinking the time delay relay possibly. If I put direct power to the fan it runs fine just not during normal operation

I came across a post on some hvac site where they were walked through testing the leads with a voltmeter but now I can't remember what i searched for to find it. Just want to make sure thats the issue.

Looks like the time delay was incorporated into a newer version of the board which is 80 bucks.

 

[frankush]

The model number of the unit would help.

 

[dave67fd]

Depending on your model, the fan should be connected to the control board on terminal EAC (black wire) and terminal "U" (white wire) OR black wire on "HEAT" terminal and white tied to common neutral.

Confirm the connections are tight, clean and not loose. The control board maybe the culprit.

You didn't mention if this is a new unit or had been running regularly in the past.

See page 18
http://www.qcsupply.com/media/pdf/modine/HD_IOM_2011.pdf

 

[Draven8795]

Sorry it's an HD30AH it's been running fine for two years since I bought it.

Then I came outside and noticed it was on with no blower fan. Thanks for the diagram much easier to read there then trying to in the heater itself I think mine is an older version with the Time Delay Relay.

If someone could walk me through testing that to make sure it's the culprit before i put the new board in.

I've checked all connections and took the flame sensor out to make sure it was clean, it was.

 

[frankush]

A couple of links to check out.

http://www.modine.com/techsupport/t...lMain/showProduct&_pageLabel=partsHomeDefault

http://www.modine.com/publications/litsearch.php?srchcrit=75-551

The time delay relay seems to be available as a separate part. You need to check the voltage across the contacts of this relay, when the unit is calling for heat. You should have voltage at startup. After the time delay times out, the contacts should close and the blower should start. If it doesn't, measure the voltage across the contacts. If you're still reading 120V, the contacts are not closing. Jump across those contacts and if the blower runs, the relay is bad. Be careful.