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scott2020

join:2008-07-20
MO

Heat Pump won't come on

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Hi,
I have a heat pump from Thermal Zone ( don't have exact model on me right now). I have attached the thermostat wiring and what is inside the air handler. The problem I have is when the thermostat is on HEAT mode, the heat pump outside unit never kicks on. After a few seconds the system goes into AUX heat. This stat has both B and O, and nothing connected to B currently. It is a Honeywell simple thermostat, nothing with programming or anything.

A guy came out and pressed on the contactor (?) on the outside unit to force it to run in heat pump mode. It came on fine and seemed to be making the "insulated" pipe hot, which is normally cold in cooling mode. The cooling mode works great and kicks on as you would expect. Sorry for not knowing the technical terms!

Anyway, we think it might be the thermostat isn't wired correctly or perhaps isn't a good one for this setup. I am thinking of trying another thermostat. I know some of the more modern ones can be set to the type of heat pump system you have, to toggle whether or not the reversing valve is energized for heat or cooling depending on the system.

Thanks for any ideas or suggestions!


Caddyroger
Premium
join:2001-06-11
To the west
Have this been working correctly before?
--
Caddy


scott2020

join:2008-07-20
MO
No it hasn't. We recently moved to this house and it is about 10 years old. The previous owners had no idea the heat pump mode was messed up. All the years they lived here, they were heating the house with expensive AUX heat! The inspector noticed when he was testing the system that the outside unit never kicked on in heat mode.


nunya
LXI 483
Premium,MVM
join:2000-12-23
O Fallon, MO
kudos:12
reply to scott2020
Before you buy a new thermostat, verify it isn't working by testing with a VOM. It would be silly to get a new t-stat without checking first.
--
...because I care.


leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
·SONIC.NET
reply to scott2020
The picture from the air handler is not very useful, it doesn't show where any of the wires from the thermostat are terminated. Yellow (Y) and orange (O) wires for cooling seem to just pass through the air handler however the purple (W1) wire for heating seems to change color which may cause confusion at the other end of the cable.

The wires inside your thermostat base are:

G - Fan (turns on fan in air handler)
C - Common (ground for the thermostat)
R - 24V AC (power for the thermostat and all the control outputs)
W1 - Heat (stage 1 heat, should turn on heat pump)
Y - Cool (should turn on heat pump and in some models is connected to W/W1)
O - Reversing Valve (powered when cooling)
B - Reversing Valve (powered when heating)
E - Emergency/Auxiliary Heat

Depending on the reversing valve either O or B or both may be needed. It seems in your case only O is used.

With the thermostat calling for cooling you should be able to measure 24V AC between:
C and Y
C and O
With the thermostat calling for heating you should be able to measure 24V AC between:
C and W1
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jack b
Gone Fishing
Premium,MVM
join:2000-09-08
Cape Cod
kudos:1
reply to scott2020
I'm not surprised it won't work, given the "workmanship" detailed in the subbase wiring connections, if that is any indication of what we can't see.
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nunya
LXI 483
Premium,MVM
join:2000-12-23
O Fallon, MO
kudos:12
That probably should have been the first thing pointed out - the obvious.
Re-terminate all those wires properly.
--
...because I care.


scott2020

join:2008-07-20
MO
I'll verify the wiring, but it looks like the white is connected to W1 and blue is connected to E. At the air handler I think those are wrapped together with the orange and black at the air handler? I'll take some readings and see what I get. I have two of these in the house. The other one is the exact same thermostat but on a smaller heat pump and air handler for the other part of the house, and they both exhibit the same symptoms. Thanks for all the replies!


SandShark
Long may you run
Premium,MVM
join:2000-05-23
Santa Fe, TX
kudos:3
If the indoor and outdoor units are by the same manufacturer, generally you can compare the wiring diagrams between them and figure out which wires go where. Just be sure to kill the power to both units before you start sticking your fingers in them.


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
said by SandShark:

If the indoor and outdoor units are by the same manufacturer, generally you can compare the wiring diagrams between them and figure out which wires go where. Just be sure to kill the power to both units before you start sticking your fingers in them.

Don't think that will work as the OP says the other unit has the same symptoms.

quote:
I have two of these in the house. The other one is the exact same thermostat but on a smaller heat pump and air handler for the other part of the house, andthey both exhibit the same symptoms.


scott2020

join:2008-07-20
MO
Everything for both systems is Thermal Zone, inside and outside units, and both have the same Honeywell thermostat.


SandShark
Long may you run
Premium,MVM
join:2000-05-23
Santa Fe, TX
kudos:3
reply to Jack_in_VA
said by Jack_in_VA:

said by SandShark:

If the indoor and outdoor units are by the same manufacturer, generally you can compare the wiring diagrams between them and figure out which wires go where. Just be sure to kill the power to both units before you start sticking your fingers in them.

Don't think that will work as the OP says the other unit has the same symptoms.

quote:
I have two of these in the house. The other one is the exact same thermostat but on a smaller heat pump and air handler for the other part of the house, andthey both exhibit the same symptoms.

Sure it will. They're miswired.


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
said by SandShark:

said by Jack_in_VA:

said by SandShark:

If the indoor and outdoor units are by the same manufacturer, generally you can compare the wiring diagrams between them and figure out which wires go where. Just be sure to kill the power to both units before you start sticking your fingers in them.

Don't think that will work as the OP says the other unit has the same symptoms.

quote:
I have two of these in the house. The other one is the exact same thermostat but on a smaller heat pump and air handler for the other part of the house, andthey both exhibit the same symptoms.

Sure it will. They're miswired.

Can you imagine the electric bills the previous owners must have had? Two heat pumps running on heat strips?


Sly
Premium
join:2004-02-20
Chuckey, TN
kudos:1
Reviews:
·Callcentric

2 edits
reply to scott2020
Disconnect the brown wire at W1 and hook the white wire up to it.

The brown wire goes nowhere... Look at your air handler. It's not hooked up. But the white wire is. The white wire at your thermostat should be hooked to W1 on your stat. If the other heatpump does the same thing then it probably has the same problem.

TURN off the power before you do this. You don't want to accidentally short out your transformer while you are moving wires around.

[edit] Never mind. Optical illusion. It looked to me like the brown wire was hooked up. I didn't see the white wire underneath it.


Sly
Premium
join:2004-02-20
Chuckey, TN
kudos:1
Reviews:
·Callcentric
reply to scott2020
Place a jumper between red and white (R) and (W1). If the heat pump comes on then you have a bad thermostat. Whatever you do, don't short red and black or you will possibly fry the transformer. If red and white do not turn on the heat pump then take apart the wire nut with the white wire in it at the air handler and make sure all the wires are stripped and are making full contact. Twist them together well and then put the wire nut back on it.


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
said by Sly:

Place a jumper between red and white (R) and (W1). If the heat pump comes on then you have a bad thermostat. Whatever you do, don't short red and black or you will possibly fry the transformer. If red and white do not turn on the heat pump then take apart the wire nut with the white wire in it at the air handler and make sure all the wires are stripped and are making full contact. Twist them together well and then put the wire nut back on it.

The OP said his second unit has the same problem so what's the odds of two bad thermostats?


Sly
Premium
join:2004-02-20
Chuckey, TN
kudos:1
Odds are slim but for trouble shooting you have to start somewhere.


cowboyro
Premium
join:2000-10-11
Shelton, CT
reply to scott2020
Test the HP by triggering its control directly, that is the easiest way.
Disconnect from air handler, apply the signal to the run wire and mess with the O/B valve to switch from heat to cool (switch compressor off before triggering the valve). Once you can confirm it is running you can go ahead and test through the air handler.


pende_tim
Premium
join:2004-01-04
Andover, NJ
kudos:1
Reviews:
·Comcast
reply to scott2020
What kind of thermostat do you have? Is it a "universal" type that can be setup to be used on different systems? If so you may want to make sure the thermostat is setup correctly for a single stage heat pump with electric aux heat. Also make sure the differential between the Heat Pump and Aux heat is set to a reasonable ( 3*-4*) value.

Since you have 2 units acting the same, this is real a long shot. but if there is an outside thermostat that determines the "balance point" between Heat Pump and Aux heat make sure this is set to a reasonable temperature. Some units have this feature to change operation to the Aux heat when the outside air temperature is too low for the Heat Pump to .
Tim
--
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scott2020

join:2008-07-20
MO
reply to Sly
said by Sly:

Place a jumper between red and white (R) and (W1). If the heat pump comes on then you have a bad thermostat.

Thanks, I will take a look at that.

said by pende_tim:

What kind of thermostat do you have? Is it a "universal" type that can be setup to be used on different systems?

Unfortunately I don't have a pic with me, but it is a Honeywell and I'll get the model number today. I need to search for the documentation and see if it has that setting that can be changed. One of the reasons I'm looking at other stats is to take advantage of programming and such. These are just basic ones to set the temp.

said by Jack_in_VA:

Can you imagine the electric bills the previous owners must have had?

I know that over the last 12 months, the average bill was around $255 a month. I don't know what it was in the winter, but for a 5000 square foot all-electric house I don't think that is too bad!

Thanks again!


scott2020

join:2008-07-20
MO
reply to Sly
I tried a jumper between R and W1 and nothing happened. I did this with the thermostat off the wall, but I am thinking it needs to happen somewhere else?

69-1486 - T8411R is the model of thermostat. It is made for heat pumps apparently, but reading the install manual I don't see where there is an option for B or O to trigger the reversing valve.

iknow
Premium
join:2012-03-25
said by scott2020:

I tried a jumper between R and W1 and nothing happened. I did this with the thermostat off the wall, but I am thinking it needs to happen somewhere else?

69-1486 - T8411R is the model of thermostat. It is made for heat pumps apparently, but reading the install manual I don't see where there is an option for B or O to trigger the reversing valve.

you said it works fine by manually operating the relay. so either the thermostat is miswired, or faulty, or the coil on the relay is open. anyway, a connection between R and W1 should have made the compressor kick on, in any mode. depending on the B or O wiring if used.


leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
·SONIC.NET
reply to scott2020
You did that R + W1 test correctly (with the thermostat removed).

The fact that nothing happened indicates that the W1 (white) wire is not correctly terminated at the heat pump (it should start the heatpump). Did you have someone monitoring the outside unit while you connected R to W1 ?

There is no point in questioning the reversing valve if the compressor isn't starting at all. There is a good probability that the reversing valve is attached correctly since the cooling mode of the heatpump is working (with Y starting the heatpump and O turning the reversing valve into cooling mode).

At this point the model number and ideally the schematic and/or installation instructions for both air handler and heatpump would be good to have.
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iknow
Premium
join:2012-03-25
reply to scott2020
your purple W1 is connected to the grey on the relay, and the green is connected to the green at the thermostat, so there should be 24 Volts across the relay coil, that's what those 2 wires are for, so you need to check that. you could turn off the power, connect alligator clip leads of a DMM set for AC on the grey and green wires of the relay, and see if you get the coil voltage when you turn the power on. you can jump the W1 and R at the thermostat and check it that way too. maybe the G and C need to be jumped together to power the relay?. the G in this unit is the ground for the heat relay, as the other terminal is the W1(purple) which turns to grey on the relay coil. so maybe just a jumper from G to C will do it.


leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
·SONIC.NET
Apparently that purple? looking wire in the thermostat base is not really connected to anything and there is a white wire underneath that really connects to W1 (using a white wire for W or W1 is normal).

No control wire (any wire other then R,Rh,Rc or C) should ever be connected to C (common, ground). G is the fan control wire (when connected to R it will turn on the in-house fan in the air handler).
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SandShark
Long may you run
Premium,MVM
join:2000-05-23
Santa Fe, TX
kudos:3
reply to scott2020
I'd suggest, as has already been mentioned, to place a jumper between Y and W1, put the thermostat back on the subbase and see what happens.


scott2020

join:2008-07-20
MO
reply to leibold
I took off the cover on the heat pump itself. Here is the wiring to the control board at the heat pump:

Black = C
Yellow = Y
Orange = O
White = W2 (this might be the problem?)
Red = R
Blue = E

On my thermostat, the white wire goes to W1 and there is nothing on W2. There is no W1 at the heat pump board. I have some pics but they didn't turn out great.

The model is CH30M-1S

thanks!


SandShark
Long may you run
Premium,MVM
join:2000-05-23
Santa Fe, TX
kudos:3
said by scott2020:

There is no W1 at the heat pump board.

That's why you need to do what I suggested. That's the only way the outside unit is going to run in the heating mode.


scott2020

join:2008-07-20
MO
said by SandShark:

said by scott2020:

There is no W1 at the heat pump board.

That's why you need to do what I suggested. That's the only way the outside unit is going to run in the heating mode.

Just so I don't screw up too bad, keep the white wire on W1, then a small jumper wire from W1 to Y? I want to make sure I"m not to move or disconnect the white wire.


SandShark
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Premium,MVM
join:2000-05-23
Santa Fe, TX
kudos:3
The white wire is not connected to anything at the outside unit, so it won't matter. Yes, a small jumper.