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Re: Trying to understand wiring for heating system

The powerpile/milivolt gas valve system is its own power source — the power pile itself (sort of a takeoff on a thermocouple) generates a very small voltage proportional to its temperature — which is sufficient,, if it's warm enough — to open the gas valve. So… the powerpile is heated by the pilot flame, and when the circuit through the gas valve is closed the gas valve opens and the burner operates.

No outside transformer needed!

However. It's pretty weak. So any problems in the wiring — or the switch calling for heat — can defeat it.

Therefore… use the X1 and X2 contacts, which are intended for very low voltage and very low current (there is a reason that Taco notes they are for powerpile/millivolt use!) rahter than A and B terminals which are intended for switching literally hundreds of times the voltage and current (120 volts at several amperes) of the X1 and X2. but which may have much too much resistance to switch the millivolt power.

Jamie Hall

Re: pls help me id "epoxy" substance

Hi, Can I hazard a guess that this is a drain line? If so, A good fix would be to cut out the cracked part and use no-hubs to replace the pipe. Some Band-aids like stretchy silicon rubber tape can last a very long time, but are still considered a patch. As the cast iron loses integrity, other problems like sagging can crop up, which is a reason to go with the most durable fix. In the long run, this will save you time.

Yours, Larry

Larry Weingarten

Re: Cleaning HVAC Ductwork?

Unless they run a camera thru the entire ductwork, live, to prove to you that it's actually ALL clean and sanitized. Which they won't, because it won't be.

HydronicMike

Re: Cleaning HVAC Ductwork?

@JMWHVAC

Your right but it wasn't always that way. With modern burners and boilers, I don't consider oil boilers dirty but they have to be set up properly.

I agree that a lot of boilers can go maybe 4-5 years without being cleaned. But they are still thing that need to be done during a proper tune up. Nozzle, filter, electrodes check combustion and oil pressure and test safety controls as a minimum. In fact the nozzle can go many years with clean oil.

EBEBRATT-Ed

Re: Adding a radiant manifold to existing single zone loop

I would purchase a Taco SR 502 (or 503) to operate the zone one and the zone 2 circulators separately using separate thermostats. Here is that diagram

Screenshot 2025-09-28 at 11.11.24 AM.png

Any Questions?

EdTheHeaterMan

Re: Need help with Radiant How to go laying panels over existing floor

Thank you everyone for the input, I agree abandon redoing the floor especially having to modify the rest of the house for the new height. @PC7060 The boiler is going to have to have re-piping done regardless of which way I choose to go. Which I'm looking at going towards the Ceiling heat option.

@hot_rod Can you refer me to any training for radiant installation? for the future? any suggestions would be great, or books/ literature . Thank you for your time

Mail4tommo

Re: Help with screw nut

Be advised we can be more powerful than the metal, it may fail when you succeed.

Lance

Re: Where's the capacitor?

Good luck finding one. I'd like to know how you determined the capacitor was bad if you couldn't check it (didn't know where it was to check it).
I can tell you since those motors first came out, I've never replaced a capacitor. Can't even remember replacing a psc burner motor in the last 8 years.

What problem are you having?

STEVEusaPA

Re: Cost to clean a heat exchanger?

@dandub1960 @mattmia2 @HVACNUT @EdTheHeaterMan @Alan (California Radiant) Forbes @captainco

I wanted to follow up on original post because I appreciate everyone's help and wanted to thank you. I had the original installer of the boiler come out and ran another combustion test (results in image). Tech took the sample from under the draft hood. We also discovered a little nozzle looking piece on the ground next to boiler. I believe he said it was an orifice that goes over the pilot burner, and without that orifice on there the pilot would be burning unrestrained and could give some crazy numbers in a combustion test. So basically the tech who took the original test sampled from wrong location and did not reassemble all the parts!

Evan0307

Re: Cost to clean a heat exchanger?

Did the tech leave behind a printout of the combustion test? At 3 years old, that boiler should be spotless inside. At 20 years it should be spotless. If there's soot, then the tech needs to find out why, not just clean it.

HVACNUT