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[mingom]

Hey guys, new to the forum.

I have a woodmaster 4400, with setpoints of 175 L and 180 H. Comes into the house via pex, into a liquid to liquid heat exchanger at which the honeywell aquastat is attached to the OWB side. The piping then runs from this to tie into the home loop, which consists of 7 zone valves, a Crown propane boiler w/tankless hot water.   My issue is that my propane boiler keeps having to come on for some reason, I've burned way for fuel than I thought I would have to.  I think the issue could be a setpoint with the aquastat or on the propane boiler.  Any ideas?  Any help would be appreciated.

[mcarter]

Seems like someone posted on this same issue not long ago, I cant seem to find the post though.

[Ridgekid]

It was mtjag. Not sure how he resolved it.

I think dean186 helped.

[RSI]

What is the aquatat connected to?

[mingom]

Aquastat is clamp on style on 3/4" copper

[Ridgekid]

I think he means where on your system is the aquastat located.

[mingom]

On the copper piping between the pex from the OWB and the heat exchanger

[Ridgekid]

Do you know what you have it set at? ( the aquastat)

[mingom]

Currently set at 70, down from 80 yesterday at the suggestion of someone on another forum.  Trying to get it from kicking on the propane. I just had the tank filled a week or two ago (120 gal tank filled to 80 percent. Woke up today and it was at 65!) Other appliances use it also so I know its not just the furnace, but its the main draw.

[Ridgekid]

It almost sounds like it doesn't even see the aquastat.  yet you said there is a delay before the propane kicks off, whereas it should not even be coming on.

Is there a pump circulating water from the hx to the boiler? It sounds like your boiler cools off a lot between cycles.

Any pumps on the zones? Or just valves?

I'm probably wrong since I don't know these type of systems, but maybe the aquastat should be on the line coming from the hx to your boiler, making the circulating pump come on when ever the temp drops below xxx*?  Or turning off when it reaches xxx*?  (probably the latter is better).

Just thinking out loud.

[RSI]

I mean what does the aquastat control?

[mingom]

Aquastat comes off the incoming line from the boiler, and the wiring runs back to a taco SR501 zone controller.

[RSI]

Could you wire in a relay that kills power to the tankless boiler?

[MTJAG]

Mingom,
On your Crown propane boiler, is there a removable cover on the side or front?  There should be a thermostat under the cover that is wired into your Taco Zone controller.  I have a Weil McClain boiler and mine was set for 165.  I set it to it's lowest setting of 140 and now mine doesn't kick on at all.  The other thing you might check is the pump at the OWB to make sure it's pumping enough.  In my case, I have Grundfos Alpha pumps that have software built in to provide variable speeds and pressures to optimize flow rates while reducing energy consumption.  I did discover that I had to set my pump to a higher level to ensure adequate return to the OWB as it would optimize and only flow at 2 GPM.
Anyway, hope this helps.

[mingom]

It looks to me that the boiler is set low one side is at 120 and the other is at 140, with a differential of 20 set.  I was really hoping that was going to be it.  I need to put temp gauges in line, but will have to wait till the summer. It could be the pump, but feeling all the pipes they are too hot to touch.  Guess its back to problem solving.