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RetroFit
Dec 13, 2008, 08:25 PM
I have a Rheem Heatpump and am not getting any heat when I switch it to emergency or set the thermostat high enough for the aux heat to come on. There is only 1 heating element and I have tested its continuity with an ohm meter after switching the fuses off and disconnecting the wires to the elements. I have also tested the high limit thermostat and it is functioning just fine. Is it possible that the element could still be bad? When I reconnect everything and turn the furnace on the heating element sequencer opens up the circuit after about 20 seconds and I can measure current flowing through the heating element. After a couple minutes I then shut everything down, pull the blower assembly out half way and the heating element is too hot to touch. Yet the air is still cold out of the registers. What am I missing? I have sat up there for 20 minutes measuring the current through the element to see if it is cycling but I don't see any kind of interruption in the power. I am completely baffled. Can anybody help? I know I can change the heating element if I have to, but it doesn't seem to be the problem since it is getting hot. At least it is too hot to touch.

letmetellu
Dec 13, 2008, 09:21 PM
I have a Rheem Heatpump and am not getting any heat when I switch it to emergency or set the thermostat high enough for the aux heat to come on. There is only 1 heating element and I have tested its continuity with an ohm meter after switching the fuses off and disconnecting the wires to the elements. I have also tested the high limit thermostat and it is functioning just fine. Is it possible that the element could still be bad? When I reconnect everything and turn the furnace on the heating element sequencer opens up the circuit after about 20 seconds and I can measure current flowing through the heating element. After a couple minutes I then shut everything down, pull the blower assembly out half way and the heating element is too hot to touch. Yet the air is still cold out of the registers. What am I missing? I have sat up there for 20 minutes measuring the current through the element to see if it is cycling but I don't see any kind of interruption in the power. I am completely baffled. Can anybody help? I know I can change the heating element if I have to, but it doesn't seem to be the problem since it is getting hot. At least it is too hot to touch.

Only one element for a furnace does not sound like enough, but if you are sure that is all you have then that is it.
When you checked your element with an ohm meter, did you disconnect all the wires from the element? Sometimes if you don't remove the wires you will get a reading through something else in the line.
If you checked the element with a amp meter, and if the element is say a 4500 watt element then the amps should be near 19 amps. (4500 divided by240 equals 18.75)
Yourr element has a fuse on the end of it and this is inside the furnace you can not see it from the outside. Tell us more and we will try to help.

RetroFit
Dec 13, 2008, 09:34 PM
Only one element for a furnace does not sound like enough, but if you are sure tht is all you have then that is it.
When you checked your element with an ohm meter, did you disconnect all the wires from the element? sometimes if you don't remove the wires you will get a reading through something else in the line.
If you checked the element with a amp meter, and if the element is say a 4500 watt element then the amps should be near 19 amps. (4500 devided by240 equals 18.75)
Yourr element has a fuse on the end of it and this is inside the furnace you can not see it from the outside. Tell us more and we will try to help.

Thanks for responding! Yes, I did completely disconnect the wires from the heating element before checking it with my ohm meter. Unfortunately I don't have an amp meter so I couldn't check the amps. The element is a 5kw. 5 K.W. Factory Direct Heating Element (1 Per Order some units may have up to 4 )(Rheem/Ruud): Best Buy Heating and Air Conditioning (http://bestbuyheatingandairconditioning.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=HST58386A&Category_Code=EHrhee) appears to be the replacement. I did not completely remove the element, but I did completely pull out the blower assembly and disasembled it enough to see the end (not the end where the wires connect) and didn't see a fuse. Is there a fuse in the middle? The picture from the link doesn't seem to show a fuse anyplace. It certainly seems easy enough to change, I just want to be sure before I drop $120.

wmproop
Dec 13, 2008, 10:04 PM
Maybe your heatpump hasn`t reversed into heat mode and its still sending cool air over the heating elements,, you did say "Heatpump blowing cold air "

RetroFit
Dec 13, 2008, 10:16 PM
maybe your heatpump hasn`t reversed into heat mode and its still sending cool air over the heating elements,,,you did say "Heatpump blowing cold air "

Well, it isn't cold air. It feels more like room temperature or a degree or two below. Last winter we had the heating element replaced and when it is working it feels very warm when on aux or emergency. Right now it doesn't seem to make a difference at all if it is on aux or emergency. There's no noticeable change in the temperature.

RetroFit
Dec 14, 2008, 08:20 AM
Thanks for responding! Yes, I did completely disconnect the wires from the heating element before checking it with my ohm meter. Unfortunately I don't have an amp meter so I couldn't check the amps. The element is a 5kw. 5 K.W. Factory Direct Heating Element (1 Per Order some units may have up to 4 )(Rheem/Ruud): Best Buy Heating and Air Conditioning (http://bestbuyheatingandairconditioning.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=HST58386A&Category_Code=EHrhee) appears to be the replacement. I did not completely remove the element, but I did completely pull out the blower assembly and disasembled it enough to see the end (not the end where the wires connect) and didn't see a fuse. Is there a fuse in the middle? The picture from the link doesn't seem to show a fuse anyplace. It certainly seems easy enough to change, I just want to be sure before i drop $120.

Also, I forgot to mention that I have measured the voltage at the sequencer at 24 volts. So it seems as though that is functioning properly as well. I am going to see if I can pick up an amp meter today. Right now the current through the element is the only thing *that I know of* that I haven't checked.

KC13
Dec 14, 2008, 09:37 AM
You said that you measured current flowing through the element, and that at one point it was too hot to touch. That does suggest that it is working. If you have only one 5kw heater, I imagine that your dwelling is relatively small or your area is not known for the cold temps you are experiencing now.

RetroFit
Dec 14, 2008, 11:02 AM
You said that you measured current flowing through the element, and that at one point it was too hot to touch. That does suggest that it is working. If you have only one 5kw heater, I imagine that your dwelling is relatively small or your area is not known for the cold temps you are experiencing now.

You know, sometimes it is the easiest things in life that get overlooked. I have asked for help on another forum and one respnse gave me a list of things to check. At the top of the list was to check the outside unit. I never thought to check it since I didn't think it factored into anything when the furnace was running on aux or emergency mode. Well, as it turned out the outside unit was not running at all. I pushed the reset button and it fired back up. Within 2 minutes I have hot air flowing through all my registers again.

You are correct in that the upstairs unit is not warming a large area. I think that is why the size is so small and there's only 1 element. I live in southwest Virginia and the night gets down into the 20's. So, it does get cold but it appears the mystery, at least for now, has been solved as to why I wasn't getting any heat.

I suppose the next question I'll have to ask is what can cause the outside unit to require a manual reset? As is obvious I'm sure, I don't know a lot about how all this stuff works, but I am a quick learner and know more today than I did yesterday. I do appreciate everyone's help who have weighed in to help me out.

letmetellu
Dec 14, 2008, 04:14 PM
Thanks for letting us know that you got the problem solved, so many people come on here and ask a question and get lots of advise and we never hear from them again, it almost makes you want to say "To hell with this" and go surfing on the web somewhere. So thanks again.

RetroFit
Dec 14, 2008, 07:15 PM
Thanks for letting us know that you got the problem solved, so many people come on here and ask a question and get lots of advise and we never hear from them again, it almost makes you want to say "To hell with this" and go surfing on the web somewhere. so thanks again.

Well, I appear to have jumped out of the pot and into the fire. I decided to install a digital thermostat (Honeywell RTH7500) to replace my old Honeywell T874R1475 with base plate Q674L 1520 and all seemed to be going well until my control transformer blew. I was testing the aux and emergency functions to ensure the system was switching correctly at the furnace. Aux switched on correctly but when I switched it to emergency I saw the transformer pop and smoke. So I'm sure it is toast. I just pray nothing else went out. Thankfully they aren't expensive but it stinks that it is broken "for real" now. I had 6 wires coming out of the wall. The red, yellow, green, and W1 were easy enough to see where they went on the RTH7500. But the B and X (labeled based on where they were attached to the old base plate) were a bit of a mystery. After searching for someone else who had a similar setup I went with what they said worked for them but for me it sure didn't.

Talk about feeling deflated. Looks like another couple nights without heat again.