Munchkin Service

Blackoakbob

I wonder what the age of your o2 cell is. I know that they don,t have a very long life, 3-4 years. I had an old Beckett that would eat them up every year! I have to say I,ve only had my Testo for 2 years so I have no experience as to how they fail, quickly or fade away?
I do have a question on your piping though. Do you believe there would be an effect on the output if the supply and return of your zone pumps was connected by closely spaced tees to a loop from the boiler? I'm looking at a system that is slow at warming up and is piped this way. Sorry, no pics as I am technically challanged. Best Regards.

Paul Rohrs_5

I installed this system 1-1/2 years ago

and it is purring along fine. It is 6200 sq/ft of high mass low-temp radiant floor heat plus DHW. 6 zones with zone pumps. At design conditions -10F, their biggest gas bill was $115.00

I wanted to see how this was looking in the combustion chamber and service it before heating season set in.

I had it dialed in last year with the combustion analyzer with 8.6 of CO2 and 6ppm of CO.

After servicing the boiler, I put our Testo 325M on it and got 8.6 of CO2 and 4ppm of CO. The strange part was that
with a space heating call and reset temp to the floor, I was only getting a 90.0% efficiency reading. (?)The combustion chamber was nearly pristine and the condensate neutralizer looks like it was doing it's job. I didn't have any PH test strips on me, but now realize it's something I could carry on the truck.

I had 84F out to the zone and 63F return. It was condensing like mad, but I could not get it over the 90.0% reading. Do you think I need to calibrate the 325? I think with the fuel bills they have been getting, this thing MUST be running in the mid 90's for efficiency.

Any other thoughts?

Here are some pics.

Regards,

Paul

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[Deleted User]

Ignore the man behind the curtain!!!

Sound familiar? As our good friend Jim Davis says, IGNORE the combustion efficiency number on your tester. THere are no less than a few hundred ways to get to a given theoretical combustion efficiency point. It's a combination of CO2, net stack temperatures that the tester is looking at, and in reality, the best indicator is the percentage of 02 left over after the burn. If the heat exchanger and other supporting cast of members is doing their job, the thermal efficiency will kick butt.

I've actually seen my little munchkin doing 99.8 percent ACTUAL thermal efficiency (gas meter on the inlet, flow meter on the hydronics, differential temperature recorders etc), and my Testo was telling me it's only 90%....

Also, the Testo, and others doesn't take into consideration the condensate that is a key part of the overall efficiency.

Nice install by the way.

Keep up the great work.

ME

Mark Hunt

I agree


but if you want to show the HO something, flip the fuel selection on your Testo to #2 oil. You should get over 100% efficiency when you do that. It will be just as accurate as the other efficiency numbers.

That is a heck of an install!

Mark H

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Helgy_3

I noticed your bladder tank was mounted up towards the ceiling. Is this just to save room or is there some other reason. Nice clean install.

Pinball

First of all, HTP manual says the CO2 should be at 9.5-10.5 % The CO @ >20ppm
Second, Are you checking it at low fire? in the service mode,
lock it in low fire..Test, adjust if needed then push it up to high fire and test again. The co2 should remain close to constant and the co no higher than >150ppm.
Also the gas supplly should me a min. of 3/4", that looks like 1/2"od copper tubing. It could become an issue at high fire.
Other than that, A REAL NICE install! I especially like the expansion tank mount and condensate drain set-up.leaving the documentation on the panel.with what appears to be photos is a nice touch.

Al

mtfallsmikey

Well, efficiency matters but..

The install is a work of art! I'm very happy to see so many of you "youngsters" not only embracing new technology, but taking such pride in your work! I would think a lot of HO's would be beating down the doors to get you and others like you to do their installs...Makes me proud of our industry, and Dead Men like my Dad would be proud too!

Constantin

Looks great!

The welded headers and the way you supported them is really impressive. As a a result, the pump panel looks really sharp! That's a lot of zones!

The stand for the Munchkin will make many a service much easier, but I would consider insulating the piping to and from the IDWH. It probably loses more heat via those pipes than via the jacket.

The way you supported the expansion tank is interesting. Did you mount it up there for the sake of longevity?