heating system problems

heatguy · December 2006

> I wrote about this system once before. I have a 
> little more info now, but still no pics. They 
> take water from the hot water heater, pump it 
> through a heating coil in a fancoil unit in the 
> ceiling, and return the water to the hot water 
> heater. Air blows through the heating coil and 
> distributes through a duct system. The fancoil 
> also has a dx cooling coil, with an outside 
> condensing unit. The cooling side works fine. 
> The heating side has had problems for the last 
> couple of years, and the apt. manager has been 
> unable to fix it (4 managers in 2 years... you do 
> the math). At first it would work on and off. 
> The manager would unplug the grundfos pump and 
> plug it back in and it would work awhile. Lately 
> it has not been heating at all. The whole thing 
> is controlled by a room thermostat. When it 
> calls for heat, the fan turns on. A signal is 
> supposed to open the Erie 2-way valve. When the 
> valve is fully open it closes a switch that turns 
> on the Grundfos circulator. When I first got 
> here (visiting), the pump and valve never changed 
> position. I didn't see a reason why it wouldn't 
> work, so I started checking some of the wiring 
> connections. After reconnecting the control 
> wiring to the servo in the Erie controller, the 
> gear started turning. I put everything back 
> together and everything seemed to be working 
> fine. We went out for the day and came back to 
> find it not working again. The Erie servo was in 
> the closed position and very hot. Since it was 
> closed, the pump was off. 
> 
> I'm attaching some 
> diagrams I made. I'm not a contractor. It seems 
> to be that the T-stat signal forces the Erie 
> controller open, but doesn't have a stop 
> function. In other words, I'm wondering if it is 
> trying to continue opening even though it is 
> fully open and eventually overheats? Or is the 
> Erie built to do that? 
> 
> For now I've bypassed 
> the wiring so the pump is always on and the valve 
> is unpowered and in the 'on' position so that 
> she'll have heat. I'd leave it this way, except 
> that it will be a problem when cooling season 
> comes around. 
> 
> Any suggestions? 
 
try turning your thermostat way up you may have a problem with your heat anticapator

ross_5 · December 2006

my sister's heating system

I wrote about this system once before. I have a little more info now, but still no pics. They take water from the hot water heater, pump it through a heating coil in a fancoil unit in the ceiling, and return the water to the hot water heater. Air blows through the heating coil and distributes through a duct system. The fancoil also has a dx cooling coil, with an outside condensing unit. The cooling side works fine. The heating side has had problems for the last couple of years, and the apt. manager has been unable to fix it (4 managers in 2 years... you do the math). At first it would work on and off. The manager would unplug the grundfos pump and plug it back in and it would work awhile. Lately it has not been heating at all. The whole thing is controlled by a room thermostat. When it calls for heat, the fan turns on. A signal is supposed to open the Erie 2-way valve. When the valve is fully open it closes a switch that turns on the Grundfos circulator. When I first got here (visiting), the pump and valve never changed position. I didn't see a reason why it wouldn't work, so I started checking some of the wiring connections. After reconnecting the control wiring to the servo in the Erie controller, the gear started turning. I put everything back together and everything seemed to be working fine. We went out for the day and came back to find it not working again. The Erie servo was in the closed position and very hot. Since it was closed, the pump was off.

I'm attaching some diagrams I made. I'm not a contractor. It seems to be that the T-stat signal forces the Erie controller open, but doesn't have a stop function. In other words, I'm wondering if it is trying to continue opening even though it is fully open and eventually overheats? Or is the Erie built to do that?

For now I've bypassed the wiring so the pump is always on and the valve is unpowered and in the 'on' position so that she'll have heat. I'd leave it this way, except that it will be a problem when cooling season comes around.

Any suggestions?

Steamhead (in transit) · December 2006

My first question

is whether the end switch in the zone valve is rated for a 120-volt circ. If not, it won't last and violates Code also.

But the larger problem is that unless there's a heat exchanger that isn't shown on the diagrams, this system mixes heat system water with domestic hot water. That can lead to the formation of Legionella microorganisms.

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rjm · December 2006

erie

sound to me that the motor in the zone valve is junk-- pick up a new erie zone valve and replace the head- you should be able remove the head(i think there is 2 screws that old it in place)-

ross_5 · December 2006

in response

I believe the end switch is rated properly. The side of Erie junction box has a diagram if the switch, and next to that it says 15 amp, 1/2 HP @ 125-250 VAC.

I agree about the issue of mixing heating water with domestic water. That is exactly how it is piped up, unless there is a heat exchanger and secondary pump hidden in the ceiling, which I seriously doubt. I guess this is how all these apartments are set up.

heating system problems

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