Double or Triple Aquastat

 
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Hollyfeld
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Post by Hollyfeld » Sat. Jan. 03, 2009 10:34 am

coaledsweat wrote:
Hollyfeld wrote:i disconnected the 2 wires from the TT Terminals and the pump stopped running
Something is calling for heat in your zone circuits. Check the wiring on the TACO valves and the thermostats for proper function (on/off).
Are all your zones getting up to heat? A bad TACO power head will decrease the flow to the zone quite often, it never gets enough flow through the zone to get enough heat to shut down the thermostat. I just replaced the second power head in 15 years a few weeks ago. ALWAYS power off a TACO before servicing (or using the manual overide, but you need to pull the #1 wire if you have power) for at least 2 minutes before playing with it, damage will result if you do not. The head comes off with an anticlockwise 1/4 turn. About $75-80 for the operating power head if that is what is doing it.

I doubt you need a zone relay with that aquastat, I have the same setup with 3 zones and it works fine.
The zones do get up to heat. Back in early november I tested the zone valves opening and closing with the thermostats calling for heat and all was good.

If something was calling for heat, wouldn't the stoker be activated at the same time?

Would a bad power head be calling for heat, but at the same time remain closed? I have two new power heads just laying around...somewhere.

IRT Steevesj - I've noticed that I need to have the boiler at 180/200 in order to maintain the heat in my house during these cold/windy days. I never knew what the oil boiler was set at when using that to heat the house, but I do know I never had a problem heating the house to whatever temp I wanted. I think during the install of the coal boiler, the controls on the oil were changed when we were playing around with them.


 
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Post by coaledsweat » Sat. Jan. 03, 2009 11:03 am

Hollyfeld wrote:If something was calling for heat, wouldn't the stoker be activated at the same time?

Would a bad power head be calling for heat, but at the same time remain closed? I have two new power heads just laying around...somewhere.
No, the aquastat tells the stoker to run based on the water temperature in the boiler, nothing else. It does not care what the zones are doing. The pump runs from the TT terminals, that side of the aquastat just looks for a call for heat, it doesn't care what the temperature is unless it gets to the minimum setpoint and then shuts the pump down for DHW supply priority.

A bad power head can fail completly or marginally. The coil may not open the valve at all, in which case you will get no heat. If it is weak and opens the valve a little, you will get some flow, just not enough to really heat the zone up enough. One way to tell is to isolate the suspected zone (turn the other zones down and crank up the suspect) and feel the return pipe. It should eventually get very hot, if it doesn't get more than warm, you have a bad coil more than likely.

 
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Post by Hollyfeld » Sat. Jan. 03, 2009 11:12 am

If there was a bad head controlling the upstairs loop, would that coincide with me having to have the boiler set at 180/200 just to keep the house warm? In the past I have done what you mentioned to do. That's when I discovered that 2 flow control valves were incorrectly set and not allowing enough heat to get to the loft in the upstairs loop. Since changing the settings on the flow valves, the upstairs heat can be maintained, but during the cold days, the boiler has to be set at 180/200. I would like to be able to maintain the heat with lower boiler settings...

So where are we with finding out why the circulator is always running? Should I hunt down the 2 new power heads and replace them?

 
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Post by coaledsweat » Sat. Jan. 03, 2009 1:09 pm

Hollyfeld wrote:If there was a bad head controlling the upstairs loop, would that coincide with me having to have the boiler set at 180/200 just to keep the house warm? In the past I have done what you mentioned to do. That's when I discovered that 2 flow control valves were incorrectly set and not allowing enough heat to get to the loft in the upstairs loop. Since changing the settings on the flow valves, the upstairs heat can be maintained, but during the cold days, the boiler has to be set at 180/200. I would like to be able to maintain the heat with lower boiler settings...

So where are we with finding out why the circulator is always running? Should I hunt down the 2 new power heads and replace them?
Yes, it could. The heads don't always fail completly. They more often than not just get weak enough so they cannot open the valve all the way. The less the valve opens, the less heat you will get to your radiators. If you are not getting enough water through your radiators, running hotter water through them will help warm the house but not a lot. Once a zone has been running a while, the return water should get fairly hot, if it is not, it is moving too slow through the radiation circuit and the volume needs to be increased. You should not need 200* water to heat with unless it is well below zero outside.

I would disconnect the #1 wire on the two zones and use the lever to manually open them (be sure to power down and insulate/tape the wire end before repowering). Your house should warm quickly if it is the valve operators. Doing this one at a time can isolate the bad one for you if that is the case.

If that isn't it, my guess is a bad thermostat or incorrect wiring in the zone circuit. You mentioned the overheat control was wired to a zone, perhaps there is a power feedback through that connection? Wires may be cattywampus?

 
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Post by Hollyfeld » Sat. Jan. 03, 2009 1:27 pm

coaledsweat wrote: If that isn't it, my guess is a bad thermostat or incorrect wiring in the zone circuit. You mentioned the overheat control was wired to a zone, perhaps there is a power feedback through that connection? Wires may be cattywampus?
Maybe this is wired incorrectly. The red wire goes to the power outlet where the zone valves get power. The white wire is spliced into one of the wires coming from the zone valve that controls the upstairs. If I wanted to connect this white wire directly to the zone valve, what terminal would it connect to?

EDIT - Im off to get some new TT wire and rewire everything.

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0103091325.jpg

Connections at 4006B

.JPG | 96.7KB | 0103091325.jpg

 
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Post by coaledsweat » Sat. Jan. 03, 2009 2:40 pm

Let us test the overheat contol first. If it is set about 20* over the boilers operating temp, the circuit should have no power going through it to the white wire. You should have 24 volts at the red and 0 volts at the white. If so, the control is OK.

Next, remove the white wire from wherever you connected it at it's other end in the zone and see if the pump stopped running.

Didn't you remove this stuff and the pump kept running before?

 
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Post by Hollyfeld » Sat. Jan. 03, 2009 4:11 pm

My voltmeter just crapped out on me (and I was just looking at new ones at the hardware store), so I cant test the voltages. I did disconnect it before and the pump still ran. I just disconnected the white wire from where it's connected in the zone wiring and the pump still ran.

EDIT - I disconnected the wires from the #1 Terminal on both zone valves. Opened them up manually, and turned off both thermostats. I was following the wires when I suddenly heard water rush back from the expansion tank (just like what happens when I turn off the boiler and pump stops). I placed the screw driver to the pump and the other end to my ear and the pump was off.


 
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Post by Hollyfeld » Sat. Jan. 03, 2009 5:21 pm

Perhaps it's my thermostat?

I have a similar model to this one
**Broken Link(s) Removed** but it's the tx1500b. The instructions for mine can be found here
**Broken Link(s) Removed**.

Here is the wiring diagram from the instructions of my thermostat. The yellow wire is connected to the "W" terminal and the red wire is connected to the "RH" terminal.
thermo.jpg
.JPG | 32.5KB | thermo.jpg

 
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Post by Hollyfeld » Sat. Jan. 03, 2009 5:47 pm

coaledsweat wrote:
Hollyfeld wrote:If something was calling for heat, wouldn't the stoker be activated at the same time?

Would a bad power head be calling for heat, but at the same time remain closed? I have two new power heads just laying around...somewhere.
No, the aquastat tells the stoker to run based on the water temperature in the boiler, nothing else. It does not care what the zones are doing. The pump runs from the TT terminals, that side of the aquastat just looks for a call for heat, it doesn't care what the temperature is unless it gets to the minimum setpoint and then shuts the pump down for DHW supply priority.

A bad power head can fail completly or marginally. The coil may not open the valve at all, in which case you will get no heat. If it is weak and opens the valve a little, you will get some flow, just not enough to really heat the zone up enough. One way to tell is to isolate the suspected zone (turn the other zones down and crank up the suspect) and feel the return pipe. It should eventually get very hot, if it doesn't get more than warm, you have a bad coil more than likely.
I'm losing my mind trying to figure this out. :bang: :blowup:

You mentioned that the stoker only runs based on the water temp in the boiler. I just noticed that when a zone calls for heat, the stoker turns on. When I manually open a zone valve the stoker turns on - when I close it, the stoker turns off.

I replaced the Taco powerheads, but decided that I will rewire them tomorrow. As of right now: No zones calling for heat, hi/lo set to 160/180, pump is off. Timer just activated stoker, pump is off. Timer deactivated stoker, pump is off. Manually opened upstairs zone valve, stoker came on, pump came on. Closed that zone, stoker and pump turn off. Do the same to the basement zone and the same thing happens.

:shots:

 
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Post by coaledsweat » Sat. Jan. 03, 2009 7:24 pm

Hollyfeld wrote: You mentioned that the stoker only runs based on the water temp in the boiler. I just noticed that when a zone calls for heat, the stoker turns on. When I manually open a zone valve the stoker turns on - when I close it, the stoker turns off.

I replaced the Taco powerheads, but decided that I will rewire them tomorrow. As of right now: No zones calling for heat, hi/lo set to 160/180, pump is off. Timer just activated stoker, pump is off. Timer deactivated stoker, pump is off. Manually opened upstairs zone valve, stoker came on, pump came on. Closed that zone, stoker and pump turn off. Do the same to the basement zone and the same thing happens.
Yes, I forgot that one point. Once the boilers temp hits the high limit and shuts down the stoker, on it's way back down the stoker will run on a call for heat from the thermostat. My bad. It still should have nothing to do with the pump running constantly though.

That is weird. If your TACOs are not wired to the power, it must be getting the feedback through the thermostat somehow. I'm going to look for the TACO drawing. Are there two or three wires on your TACOs? Are any wires attached to the powerheads?

 
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Post by SMITTY » Sat. Jan. 03, 2009 7:54 pm

I don't know if this will help..........

I have a zone valve that is malfunctioning, & it will cause the boilers circulator to stay on constantly, which will also cause the oil burner to run needlessly until it reaches the hi limit. I wired up a green LED to the circulator so I can tell when it's on or off over all the noise. Whenever that light is on, I check all 3 zone valves to see if they are open by pushing down the lever manually. If they are open, the lever moves very easily. Often I check & all 3 zones are closed, but the circulator is still running...... (after alot of trial & error, I've narrowed it down to the zone valve for the 2nd floor) so I move the lever on that bad valve a few times & it shuts off. Used to happen constantly, but now seems to happen less, now that the zone is used every day since I installed the coils in my stove . That particular zone used to never get used. When I moved in here 5 yrs ago, it wasn't even wired up, so that could be the cause of the sticky contacts in the head.

Since you replaced the heads, maybe that fixed the issue? Sounds like they're working properly if everything runs with the lever pushed down.

 
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Post by coaledsweat » Sat. Jan. 03, 2009 7:57 pm

OK, what it is doing is correct. The #1 wire is the feed from the thermostat. That energizes the valves coil, when it does that, it closes a switch to the TT terminal and turns on the pump. That is why the manual actuation of the valve acts as a call for heat to the TT terminals.

I'll go look for the drawing online now.

Here you go, it's the intermittent pump one.

http://www.taco-hvac.com/uploads/FileLibrary/100-3.2a.pdf

 
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Post by Hollyfeld » Sun. Jan. 04, 2009 8:04 am

coaledsweat wrote:
Hollyfeld wrote: You mentioned that the stoker only runs based on the water temp in the boiler. I just noticed that when a zone calls for heat, the stoker turns on. When I manually open a zone valve the stoker turns on - when I close it, the stoker turns off.

I replaced the Taco powerheads, but decided that I will rewire them tomorrow. As of right now: No zones calling for heat, hi/lo set to 160/180, pump is off. Timer just activated stoker, pump is off. Timer deactivated stoker, pump is off. Manually opened upstairs zone valve, stoker came on, pump came on. Closed that zone, stoker and pump turn off. Do the same to the basement zone and the same thing happens.
Yes, I forgot that one point. Once the boilers temp hits the high limit and shuts down the stoker, on it's way back down the stoker will run on a call for heat from the thermostat. My bad. It still should have nothing to do with the pump running constantly though.

That is weird. If your TACOs are not wired to the power, it must be getting the feedback through the thermostat somehow. I'm going to look for the TACO drawing. Are there two or three wires on your TACOs? Are any wires attached to the powerheads?
There are 3 wires on the TACOs. I reattached the existing wires to the powerheads and was going to rewire them today because its a ball of spaghetti where they all splice together behind the boiler.

Since I don't use the set-back features on the programmable thermostat, I might install the basic one that Keystoker gave me with the boiler.

Last night the boiler was set at 160/180 and the upstairs TT was set to 68*. This morning the house** was at 65*. :(

**edit - The uninsulated A-Frame :funny:

 
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Post by BigBarney » Sun. Jan. 04, 2009 3:51 pm

Attached find a Taco zone valve wiring diagram,there are 4 wires on each valve and the

two end switches control the circulator pump through the thermostats.My system has 4

zone valves hooked up this way and all works fine.

Quote:
"That is weird. If your TACOs are not wired to the power, it must be getting the feedback through the thermostat somehow. I'm going to look for the TACO drawing. Are there two or three wires on your TACOs? Are any wires attached to the powerheads?"
End Quote

The feedback is probably coming from the overheat aquastat,it must be isolated from the other zones and treated as another

zone to run whichever zone is used for overheat protection.It cannot feed power to the circulator except when an overheat

condition exists.

BigBarney

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102-111A_EBV Zone Valve wiring_new.pdf
.PDF | 156.4KB | 102-111A_EBV Zone Valve wiring_new.pdf

 
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Post by coaledsweat » Sun. Jan. 04, 2009 7:01 pm

I believe he disconnected the overheat control and the pump still ran. The problem maybe the wiring at the overheat zone valve.


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