Not getting burner to turn on from

Peerless92

I had a heat pump water heater installed last spring. My boiler would run non stop to produce hot water for the house as it should. After I got the heat pump water heater installed the boiler no longer produced hot water which I thought was done on purpose. What is the wago clip installed for. The circulator pump turns on but it doesn’t turn on the burner.

Jamie Hall

Not sure. But it almost looks as though it bypasses the aquastat completely — and that the aquastat output doesn't connect to the boiler T-T input. Which would indeed keep the boiler from running.

I couldn't be sure of that without tracing the wiring…

What should happen is that the thermostat turns on the circulator. That in turn sends a signal to the aquastat. If the boiler water isn't hot enough for heat, that should turn on the boiler.

I'd be surprised if the water heater installer did that — but they may not have known what to do or how to do it, and thought the aquastat was only for the domestic hot water.

HVACNUT

Is anything connected to TT on the aquastat? If so, that zone should work.

It doesn't look like ZR,ZC is being used, which would output and input with the switching relay, so the boiler knows there's a heat call. The screw fell out of terminal 5. Put it back. Run a 14/2 B/X between ZR,ZC on the aquastat and 5 and 6 on the switching relay. Tape the White wire with blue or red because it's being used as a 120 volt hot, not a neutral.

Peerless92

After looking at this diagram why is the red wire and the white wire not where they are in this picture and why do they have a wago?

Peerless92

just to add more information one of my thermostats will turn the boiler on until it reaches the temp in the living room then it will shut off completely until the next time it calls for heat. The other thermostat will only turn on the circular pump but not the burner. My boiler also does not maintain a temp at all even being on

HVACNUT

https://forum.heatinghelp.com/discussion/comment/1814891#Comment_1814891

Asked and answered. Somebody altered the aquastat to be "Cold start". Kind of a MacGyver move IMO. Since the boiler no longer maintains temperature, the zone connected to the switching relay needs a way to tell the boiler "give me heat". That's what ZR,ZC to 5 and 6 does.

Peerless92

so can’t I just turn it back into a non cold start and call it a day. I’m not an expect in this but the guy who installed my water heater is denying touching the aquastat at all when in fact he did cuz I know I didn’t nor would I even know how but I’m getting no help from them.

HVACNUT

I'm not there to view the whole thing, so I would suggest you contact your oil service provider for options on repair or replacement.

Jamie Hall

Look. Your heat pump water heater sales person very likely had just barely enough knowledge to hook up his product — and should never have messed with the boiler in the first place.

As noted, you need to get your oil burner service person out there to figure out what was done and restore the system to operate correctly. Not, unfortunately, something I can help with much over the internet…