muchkin experts!

harvey

We have just installed our first munchkin 80K boiler(peerless pinnicle) and noticed some oddities. The two wires connected to TT terminals each read 60 volts from wire to ground. Is this normal? We started the boiler and it ran fine. I thought it would remain on high fire until it was close to its limit setting 130* with 30* differential but it sounded like the burner was cutting back when the supply temp was 100* and the return temp 70*.
I would like to hear (read) your comments. Thanks

munchkin-man

what two wires are connected to the tt terms

the two gray wires that connect to the molex that is connected to the control board or the two wires from another source that are connected to the two gray tt wires?
If you are talking about the two wires from another source where are they coming from and what are they connected to a switching relay? zone valves with transformer?

The conrol has a preprogramed 30* delta. The way it works is the two thermisters one on the supply and one on the return monator the two temps. When the return temp gets with in 30* or 29* of the supply temp the blower motor will start to turn down in speed. This will cause less vacuum across the venturie and the gas valve regulator will start to close down thus delivering less gas / btu's to the combustion process. your limit is set at 130* the Munchkin will not reach set point if the load it is supplying is greater than the recovery of the Munchkin so it will sit and work off the delta between the supply and return. The system seems to be responding fine.
Please clarify the wiring issue so we can check it out.

harvey

btu input

Thanks for the reply. I think I understand what you are saying about the 30* differential. We started the snowmelt zone on this same boiler. Start-up temp supply 60* return 40*. The boiler ran 100% input until your 30* differential then cut back the burner. The recovery time to melt any snow will probably be 3 months at that rate. Your comments?