Gas and Oil Home Heating Furnaces - HELP ME!! RHeem Heater Problem - Fan stays on 24/7!

Year: 1997
Make: RHeem
Model: RGVG-05NAUER
Circuit Diagram: DWG No. 90-22886-01

What happened is that earlier this January, we left the heater on and was awoken during the night. Reason is because there was no heat.. instead there was constant cool air being blown out. I tried to turn it off from the Thermostat, but nothing had worked. The FAN was set at AUTO position & the rest was at OFF (Honeywell Electric T-Stat).

Eventually, I had to turn it off from the breaker switch box. Today, a HVAC contractor came and charged me $78 for diagonstic and told me that the board needs to be replace and would cost $400 including labor. :eek: I was like what the F.

There is this thing called the Junction box, where there is a blower door switch. the HVAC said if in the even the door is opened and the switch pops out then the unit should stop. but instead the fan keeps on turning. He then disconnected the HEAT portion from the Integrated Ignition & Blower Control, but the fan kept on turning. He asked me to turn the T-stat to cold and see if that will work.. and still nothing. The compressor in the AC didn't even turn. But the fan just kept blowing cool air. So he said the board is shot.

Now, I'm a newbie at all of this.. so please help me out. Could it be that the HALC (heat assisted limit control) is fried?

thanks.
rui

It is possible that the relay on the board is stuck. The board problems I've encountered with that vintage of Rheem is that the solder joints have cracked on the back side of the board on several units.

Without checking it with a meter it's hard to tell though. If in doubt of the diagnosis get a 2nd opinion and don't mention what the other guy found.

That's about 1/3 the cost of a new furnace. The board is about a $100.00 plus their markup and labor. Shouldn't cost you more than $250 - $300 for a service company to replace.

mattison, that's what i thought too. the guy did say that the solder is probably stuck so that's why the fan and the heater is on 24/7. but my guess is that some of the fuses may have gone bad. so i'm going to check out all the PBS (push button switches) and all the HALC and see if all is well. if it still doesn't work.. then we will just have to get someone else to diagnose it and hopefully they will be able to give a different solution.

my 2 cents

as i understand the fan runs all of the time

"fan and heater are on all the time"
you mean fan and no heat, right?

there is a safety circuit on your unit that will cause just what you describe when open due to certain conditions

the high limit switch, a bonnet over temp switch which is auto reset, located on the "firewall" above (or beside if horizontal) the gas valve



rollout switches are located on the burner assembly, there may be 3 or more, they are manual reset with a red button between the wires

there may be one in the blower section as well. look for wires leading to the blower motor that do not appear to go the the blower motor itself.

you can jump these out to see if they are open if you do not have a meter, but i advise against that unless you know what you have there.

hope this saves you come bucks

most importantly, if something i mentioned fixes your problem, look further to see why the switch opened in the first place

where do you live?

hvac.. u nailed it right on the spot.. yes.. heat is on all the time, but only the fan part blowing cool air.

i live in North San Jose, California.

i'll check those places as u mentioned tonight. wish me luck...