So confused with pumps

mschaefer

I have no knowledge. But I do have a pump that is connected to my aquastat and won't stop running the boiler. Should I just disconnect aquastat from that pump? Please help!

bmwpowere36m3

The pump won't stop running the boiler? Or the pump just doesn't stop running? The pump has no influence on whether the boiler is firing or not. Sounds like a bad aquastat.... And just disconnecting the pump won't solve anything, might actually cause problems.

Call a pro!

mschaefer

The boiler will get up to 180 and then shut off. Once it gets low enough, it starts all over again. The weird part is that the thermostat is turned off.

mschaefer

I guess my question is about whether the aquastat should be directly connected to my zone circulator or should the relay operate the zone circulator? Thanks!

bmwpowere36m3

That's "normal" operation... keeps the boiler hot, either for heating or DHW. How's your hot water setup (tankless, storage tank, indirect, etc..)?

Pics of the system would be helpful.

The zone circulator should be connected to the relay, so the thermostat switches it.... However are you sure that circulator is for space heating?

mschaefer

I have a separate hot water heater; the boiler just fires for the baseboard water system. I have three zones, but only two are being used currently.

One zone has the pump connected to the relay. For some reason, the other pump is connected to the aquastat. So even when the thermostat is off, once the boiler fires up (reaching its minimum) it's pumping through the zone.

Can I just redirect the 120 line from the relay to the pump and disconnect the 120 from the aquastat to the pump?

bmwpowere36m3

Maybe someone else can chime in... but sounds like you could set up the boiler for "cold-start". Thus the boiler wouldn't fire unless a call for heat came.

mschaefer

Ahhhhh.... Many thanks!

STEVEusaPA

Why don't you make sure you don't have a problem with the aquastat or your thermostat wiring before you try to rewire. This appears to be a new problem, so just taking the circ off the aquastat isn't going to help.
What model aquastat?
Oil or Gas fired?
Can you show a pic of the wiring in the aquastat, or better yet draw a diagram?

mschaefer

I will draw a diagram. What's throwing me off right now is that when I turn my thermostat on for zone 1, it shuts the boiler off. If I turn the thermostat off, the boiler will fire and send hot water to zone 2 (which has no thermostat connected and has the circ wired to the aquastat)....

mschaefer

Honeywell for aquastat.
Propane boiler.

mschaefer

Here's a diagram (I'm neither a plumber or an artist)<img src="https://us.v-cdn.net/5021738/uploads/FileUpload/27/0246c744cd71f5776e45aecbbf9ad5.jpg" />

pugdad

Could be a bad zone valve end switch

mschaefer

Okay.... Disconnected 120 line from aquastat to zone 2 pump. Restarted boiler, went to 220 degrees, water came out emergency relief valve so I shut it down... Need help. Desperate. Pistol don't say a word. PLEASE HELP!!!

mschaefer

Also.... I don't have a thermostat connected to zone 2. If I have a thermostat connected to zone 2, 120 connected to aquastat, will that essentially monitor the temp in zone 2 and shut off the boiler?

mschaefer

Lastly, can I hook up my zone 2 thermostat in the same taco relay (sr 501) as my zone 1 thermostat?

I'm anticipated bother tstats in the same relay. Zone 1 would be powered straight to circ pump and zone 2 would be powered from the aquastat. Does this sound okay? Right? Safe?

bmwpowere36m3

Sounds like the aquastat is bad... As it should have shut off the boiler before blowing the relief valve. Seems like the circulator kept the boiler flowing, maybe keeping it from getting too high in temp.

What are the settings on the aquastat?

I would reconnect the circulator to the aquastat and consider a professional look kat the system. Blowing the relief valve is definitely a safety concern.

As far as relay, if you have two thermostat you need a two zone panel... So SR502 I believe, currently you only have a single zone relay.

Mark Eatherton

bmwpowere36m3 said:

Sounds like the aquastat is bad... As it should have shut off the boiler before blowing the relief valve. Seems like the circulator kept the boiler flowing, maybe keeping it from getting too high in temp.



What are the settings on the aquastat?



I would reconnect the circulator to the aquastat and consider a professional look kat the system. Blowing the relief valve is definitely a safety concern.



As far as relay, if you have two thermostat you need a two zone panel... So SR502 I believe, currently you only have a single zone relay.

What he said... Where are you located? You need professional help. And sooner rather than later. Runaway boilers are serious and can result in major catastrophic losses if not corrected.

ME