# No power to circulator pump



## CJW5 (Nov 4, 2015)

I own a Weil-Mclain boiler, Taco 007-f5 pump, and L8148A controller.
Pump runs, controller does not power up the pump.
I have a couple questions.
Does the controller only run the pump while the burner is running?
Money is short, and the controller is expensive can I power up the pump using the burner wire so it runs only while the burner is running without drawbacks? Thanks in advance for your help.


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## maple1 (Nov 4, 2015)

Typically the pump runs when there is a call for heat - i.e., when the thermostats get turned up.

Then at same time on call for heat, the aquastat will also start & stop the burner to maintain boiler temp.

So if you tie the burner & pump together, the pump will stop every time the boiler gets up to temp. If the 8148 aquatstat is faulty, I would replace it. $130 on Supply House website.

But I would first make very sure it is faulty. Part of a typical setup also is that there is a zone valve between the thermostat, and the aquatstat. And what actually happens is when you turn the thermostat up, it first opens a zone valve. Which has a little switch inside (called an end switch) that then closes as the zone valve opens, thereby completing the circuit that starts the pump by sending power to the aquastat. So - do you have zone valves? How many wires on them? I have never had an aquastat go bad, but have had several end switches go bad. Not saying that is your problem, and you might have a different setup, but I would throughly check out the rest of the components. Does the burner work OK? Starts when you turn a thermostat up, stops when you turn it down? If so, it might well be the aquastat. Posting a couple pics might help. How did you determine the pump runs?


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## CJW5 (Nov 4, 2015)

maple1 said:


> Typically the pump runs when there is a call for heat - i.e., when the thermostats get turned up.
> 
> Then at same time on call for heat, the aquastat will also start & stop the burner to maintain boiler temp.
> 
> ...




Thanks for the reply. It has zone valves and the valves all seem to be working as they should.

Here is the issue,

I have 4 zones (5th one in the garage) 2 zones seem to be working properly 2 zones do not. The 2 that are not working only heat half the room. Each room has 2 base board heaters and only one work in each room. One room is on the second floor and the other is right below it. The heaters that are not working are on the same side of the house. All air has been removed from the system as of yesterday with the same results.

I used a jumper wire to run the pump while the burner was on and all zones worked as they should. Any tips would be helpful.


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## CJW5 (Nov 4, 2015)

The model # on the cover is L8148A, is model # L8148A1017/U the same part? When I searched the Supply house using the first part # it came up as the second part # . Are they the same unit?

Edit: looks like the L8148A1017 replaces L8148A.


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## maple1 (Nov 4, 2015)

If you turn one of the 'half working' zones up, then turn one of the 'good working' zones up while leaving the first still turned up, does the 'half working' zone then start working good?


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## CJW5 (Nov 5, 2015)

With the boiler temp at 185* I turned on a full heat zone and a half heating zone to 90*.
After 8 mins the boiler kicked on
After a about a min running the temp needle flicked down to 165*
After the burner shut down it flicked up to 180*
The needle did not move smoothly, just moved in one flick.
The half heat zone did not change (one side hot, one side cold)
The circulator never came on
Outside temps 65*


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## maple1 (Nov 5, 2015)

Sounds odd.

Not sure what's going on with your temp guage but sounds like you might need a new one, and that one is sticking.

Also not sure what's going on with your zones & pump. If two zones are heating good, that should be a sign your pump is working. Plus the fact the burner kicked on after a few minutes & temp dropped to 165 - that's another sign. Unless - the two zones that are working, are optimally laid out for very good convection flow and the water is circulating that much from convection alone. I have two upstairs zones like that, but they still take longer than a few minutes to get heat going all around those zones.

If you have ruled out all else, and are certain the pump isn't coming on when it should (did you also check for power on the aquastat terminals where the pump is wired to?), but it will start when jumped to another power source - sounds like it's time to get a new aquastat. That's about all I can tell from here. I can think of 3 other things it could be - a stuck circ pump, bad end switches in the zone valves, and airlocks. But sounds like you have ruled those out.


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## CJW5 (Nov 5, 2015)

As previously mentioned no power to the pump, and all zones work as they should when I jump power to the pump. However, I appreciate your help and going through the diagnostics with me.

This brings me back to my 2 original questions,
Does the controller only run the pump while the burner is running?
Can I power up the pump using the burner wire so it runs only while the burner is running without drawbacks?
Most likely I'll just purchase a new one, but it would be good to know.

Edit: I just re-read your first post, if I get this right, the pump will go on when there is a call for heat but won't go on if the boiler fires only to maintain the heat? So if I wired it to the burner the pump would be on during the heat-up phase when it shouldn't??


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## maple1 (Nov 5, 2015)

CJW5 said:


> As previously mentioned no power to the pump, and all zones work as they should when I jump power to the pump. However, I appreciate your help and going through the diagnostics with me.
> 
> This brings me back to my 2 original questions,
> Does the controller only run the pump while the burner is running?
> ...


 
The pump will start every time the burner starts. And stop every time it stops.

That means there will be times when the boiler is just maintaining its temperature, that there will be heat going through your zones when there is no call for heat. (Unless you have a cold start boiler). Or, more likely, it will be deadheading against your closed zone valves.

It also means that there will be times when your zones are calling for heat and your house is wanting it, that the pump won't be running. Like, the burner starts on a call for heat and both start running, but then when the boiler gets up to temp it shuts off - which also shuts your pump off when you don't want it to. So then your boiler sits there fully up to temperature, and has to wait until it cools off from either convection thru your pipes or heat going up the chimney, before it and the pump starts again. All while your house is wanting heat.

That is skewed some by the apparent fact that some of your zones somehow seem to be getting heat good without the pump running - not sure what's going on there.


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## CJW5 (Nov 5, 2015)

Thanks for the explanation, I'll feel better about buying the aquastat now. 
Best answer I can give concerning the good heat in other zones is gravity.


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## CJW5 (Nov 12, 2015)

I now have the new aquastat and have questions.
Do I remove the threaded nut to remove the aquastat?
The new one has a lock nut, do I need an adapter to mount the new one?


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## CJW5 (Nov 12, 2015)

Found the setscrew under the box and have it off.
No adapter needed

Fired up the burner and all is working as it should. Temp needle sweeping as it should as well. Thanks


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