DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   HVAC (
-   -   Heat not working (

RuleBreaker 11-12-2010 05:51 PM

Heat not working
Hello all:

Iam having a problem with a Magic-Pack unit. I had a service technician out and he coudn't fix it. I'll try to describe the problem as best I can.

Heat was working with no problem. Now it very rarely comes on, but occasionally does work for a short period of time and then it shuts down. I have turned on/off the emergency reset switch, changed the batteries in the thermostat, turned off the thermostat,raised the thermostat to a high set point.

In all cases either nothing happens, or the blower runs for a short period, the gas burner might fire, but then it shuts down. There is clicking out at the unit as it seems to be trying to start up. I just tried setting the fan to run constantly and nothing happened. The unit was installed in March of 2009. 48000 BTU, Honeywell electronic thermostat.

I'm thinking of replacing the thermostat, least costly option, since it cost me $110 for a technician to change the batteries in the thermostat. They were my batteries. Any help would be appreciated.


yuri 11-12-2010 06:01 PM

Carefully remove and label the thermostat wires at the circuit board inside the unit. Then put a jumper wire between R and W and run the unit. If it runs normally then the tstat is the problem.

RuleBreaker 11-14-2010 08:03 AM


Thanks so much. I turned off the main switch to the heater, spliced the R and W wires together and the heat started up but shut down again. And then restarted.

I did leave the R and W thermostat wires connected when I spliced the R and W together. I will disconnect and see if that changes things. Any other thoughts?


RuleBreaker 11-14-2010 08:31 AM


The heat shut down. Now it is calling for heat again, but never ignited. LED gives 3 flashes after it tries to fire indicating a problem with the pressure switch. Then it tries to fire up again. Now it just fired up. Shut down again calling for heat. Fired up again. It's running. I took out the filter to make sure there were no air restrictions.


RuleBreaker 11-14-2010 09:00 AM

Yuri, it keeps shutting down or doesn't fire. I am nt getting clear codes that I can tell.


yuri 11-14-2010 09:18 AM

Follow the hose from the press switch to where it attaches to the collector box or ventor fan and pull it off. The ream the hole out with a small bit or paper clip. Bit is better. Blow the hose out with it detached from the switch, may have moisture in it. DO NOT suck/blow into the switch. Check the grill outside the condo for debris blocking it.

SKIP4661 11-14-2010 10:31 AM

Have seen mud daubers build nests in the venting in magic paks and cause problems similar to what you are describing.:thumbsup:

RuleBreaker 11-14-2010 03:04 PM

Damn heater has been working all day. I am getting 24 volts at the pressure switch so it's working. The hose is clear so no clogs there. I'll detach it and blow it out.

It's real tough to get to the grill. I'm up on the third floor but I'll see what I can do to check for blockage.



kenmac 11-14-2010 03:38 PM


Originally Posted by RuleBreaker (Post 534195)
Damn heater has been working all day. I am getting 24 volts at the pressure switch so it's working.

Are you measuring 24v from 1 wire off the ps to c or are you measuring 24v across the ps ? If your measuring 24v across the ps then it's not closing. You would read 24v across the ps if it's not closed

RuleBreaker 11-14-2010 04:31 PM

I measured from one wire to ground and then from the other wire to ground. It sounds like I am not testing properly. Should I use the meter to test from one wire to the other? I want to see 24 volts?



beenthere 11-14-2010 04:38 PM


Originally Posted by SKIP4661 (Post 534058)
Have seen mud daubers build nests in the venting in magic paks and cause problems similar to what you are describing.:thumbsup:

Yep. They like those heaters.

RuleBreaker 11-14-2010 04:46 PM

There does not appear to be any blockage from the limited access I have. Tested p switch across the two wires and got no voltage. Tested each wire to ground and got 24 volts. Furnace was running during testing and as soon as I put the panel back, it shutdown. Starving for air? Ist worthwhile to pull the vent tube off completely and check for a blockage?

Thanks. Greg

beenthere 11-14-2010 04:51 PM

Look for blockage.

yuri 11-14-2010 04:57 PM

Yep, putting the panel on makes it airtight and it needs to suck air thru the outdoor grill for the burner.

RuleBreaker 11-16-2010 02:12 AM

Checked the vent pipe: no blockage. Maybe the control panel acting up. I see there is an upgraded panel available which leads me to believe something was wrong with the original. What else can I check? The blower motor?



All times are GMT -5. The time now is 11:54 PM.

User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.