Best Of
Re: Domestic hot water
I might check the check. as @Kaos mentioned. when you started to heat for the first time this season the check valve may have not completely closed on the space heat side of the system. An easy to check it is if the proper valves were installed you can shut off a valve to the space heat loop to the AHU and see if the problem goes away.
The following diagram illustrates how the water can flow backwards when the circulator pump is off and the check valve is passing.
When the circulator pump is operating, the reverse flow can't happen so you get HOT water. When the circulator is not operating the reverse flow will allow lower temperature from the AHU coil to mix with the Hot water and you end up with Warm Water
Re: Gorton #2 or Hoffman 75
Hoffman products are very high quality, as are Gorton. The greater air expulsion rate of the Gorton #2, which is in the same price range and close in height, make it the better choice in most cases. Mad Dog
Re: Cost to clean a heat exchanger?
They don't make a more simple boiler. That's an open draft hood, so I hope the tech got the probe up over the top of the block. With those numbers, it seems the techs sampling was diluted. Atmospheric oxygen at sea level is about 21%, so getting 16.58% during a combustion test means the tech didn't stick the probe where it needs to be stuck.
@Evan0307 , did you see for yourself the dirty flue passages in the boiler? Dollars to donuts its clean as a whistle.
HVACNUT
Re: Cost to clean a heat exchanger?
Combustion is way off. I don't see a HX getting dirty with those #s but anything is possible.
CO needs to be below 100 below 50 is better and it should be a lot lower than that like 10
Co2 should be more like 9
O2 maybe 5-6
So your way off I am surprised it ran
But check the service manual for what the combustion #s should be mine are just a reasonable guess.
Something is way off and I suspect they never combustion tested it at start up.
Re: Cleaning HVAC Ductwork?
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.
Re: My SteamPunk boiler
Never seen that done before- it'll be interesting to see how it works out. That said, start saving for a new one. And make sure there aren't any leaks out in the system- fresh water shortens the life of a boiler.
Re: Flue pipe removal: bust up old furnace cement?
Pop the elbow out of the Tee. Leave the breach alone. I
HVACNUT
Re: Domestic hot water
These systems have a check valve between space heat and DHW. This is either an itegrated check inside the pump or a stand alone one. If this check is stuck or leaks, it creates the symptoms you see as cold water can bypass the tankless when the pump is off.
A quick check is to see if the inlet of the pump gets cold when you have a DHW draw. If it does, you need to clean/replace the check valve.
Kaos