Good afternoon,

I am experiencing some issues with my Triangle Tube Smart 40 water heater. I have a Weil McClain GV90+4 boiler. Both were installed in 2012 and were with the house when we purchased it. I’m now starting to track exact temperatures with time stamps etc, but wanted to put an initial post up in the event the general symptoms I have so far can point towards additional troubleshooting steps.

We’ve been having a bit of cold snap here in RI, and earlier this week we had a couple of nights down in the single digits. My heat wasn’t keeping up and we just had a newborn. With limited time I bit the bullet and called a HVAC contractor out. That wasn’t very helpful unfortunately, but that’s a different story. One thing he thought could be happening is that water heater was calling too frequently which didn’t allow the boiler to keep up with heat. He pulled the sensing bulb out and placed in back in just to ensure it was bottomed out. I’ll outline the issues I was having before and after the technician came out.

Before:
• Water temperature in shower dove quickly. Rebuilt the Symmons valve with new spindle & seats, helped the issue.
• This led me to start playing with the temperature of the water heater. At the same setting at the kitchen tap (first hot water fixture off it) sometimes I would get ~118, others ~140. It also would drop ~10 degrees within in a minute or so of running.
• I initially thought the dip tube might be broken, but from my understanding that wouldn’t cause large fluctuations in the “sitting temperature” of the water heater, only once you start drawing you would see a sudden drop.

After:
• Pulled out and put back the sensing bulb, bottoming it out. He set the water heater thermostat back to the middle setting, just before the scald hazard warning.
• My boiler was set to 187, he dialed it back to 180 since “that’s where it should be”. This was concerning as he didn’t seem to consider at any heat load calculations (never asked size of the house, insulation quality, etc) just arbitrarily dialed it back amid a cold snap when the heat was already struggling to keep up.
o As a side note, this resulted in my house dropping even further, on a night it went down to 3 degrees outside, I set the boiler to 195 and that managed to keep the house at 68 but wouldn’t satisfy the 70 degree thermostat setting.
o After temperatures returned to normal, I set the boiler back to 185.
• Last night, when checking the water heater temperature, it was at ~137. Boiler temperature was 185 at the time.
• We dropped into low single digits last night, so I set the boiler back to 195 as the house was losing temperature again.
• This morning the water was 151 at the faucet. Boiler temperature still 195, water heater set to the middle, before the scald hazard.

I’m wondering if my water heater thermostat is bad? In both boiler temperature scenarios, the water heater mid-point temperature setting appears to be way too high (Especially 151). I would think a higher boiler temperature was just result in faster recovery of the water heater, not a significant increase in its temperature.

Please let me know if there is any other information required, or clarity. Sorry for the long post and appreciate taking the time to read through my ramblings.

As a side note, I ordered an infrared thermometer to I can check my baseboard temperatures to try and troubleshoot the boiler keeping up. I think the house may just be leaky.

Edit: I should note DWH priority is set to "On"

Edit 2: Forgot to mention the expansion tank is blown on the boiler circuit - unsure if that would cause the heating issues I've been having. Wanted to mention in the event this could impact the water heater zone.



Edited 2 times.

180 deg boiler water is not hot enough to heat the house when it is near zero outside.

Alot to unpackage here Brono. Let's start with what is the sq footage of house, year built and input of heating unit

2) is there a separate control box with maybe a little lite that says domestic priority and is that set to on

3) do you or anyone in the house take long baths during this cold snap

4) do you turn the heat down when you leave the house.



Edited 1 times.

Good evening,

1. The house is a 1385 sqft ranch. Built in 1972, and an addition added in 1991. 84,000 BTU

2. Zone 4 hot water priority is set to On

3. My wife and have been showering once a day, about 10-15 min each. Every other day we fill the tub for our son.

4. Heat has remained at 70 on one zone, 68 on the other.

Thanks!

Edit - Added BTU output of boiler



Edited 1 times.

Man, that is close, almost just enough to heat the house forget the hot water. look at it this way...that boilers just making it to heat the house (at single digit outside temps) .... now the demand for hot water shuts down the heating zone to make domestic hot water, that could take 20 minutes or so, then the boiler has to play make-up time and time again. Do you turn the heat down when you leave the house? You might have to shut off that priority switch. Boiler is under sized.At the very least do what Packy said and kick that boiler temp up to 200.. say are there and large sliding glass doors you forgot to tell us about ? .. any zones you can turn down?



Edited 2 times.

Thanks for the help so far, and sorry for the delay been a busy couple days. Once I turned the boiler up to 200° on the 3°night it kept managed to keep up. One side of the house which has the bedrooms, with the thermostat in the hallway at 70 , and the other which is an open living/kitchen/dining room at 68. I didn't raise them at all to see if the boiler had to ability to push this further, but it got by, if just barely. We're in the middle of going through a state-sponsored energy efficiency upgrade they've already done the air sealing, but still need the blown-in in the attic so we'll see.

Is it ok to run the boiler at 200? Or should I dial it back down to 180 during normal winter temps?


As for the water heater, I'm still having the issues. I haven't changed the thermostat's position from approx 1/4 of the way up from the lowest setting, and my hot water temps at the faucet are still fluctuating. 150 last night, and just checked it now at 127. Is the thermostat bad?

Thank you!

dial the boiler up and down as much as you want.

as OFTEN as you like

not necessarilly as MUCH as you like

think BLEVE from superheated water

(boilers do NOT have T-PRVs, merely PRVs)





boiling liquid expanding vapor explosion, as in (superheated) water flashing to steam occupying 1,700 times the volume

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Ok thank for the input on that. For clarification, when you say nit as much, is the fact the boiler has a 200° Max temperature enough of a safety buffer to not have to be concerned? With that said is there any disadvantage to just leaving the boiler at 200° (Or maybe lower but, greater than 180 based on the answer to my previous question) rather than intermittently turning it up and down?

Lastly, the replacement thermostat and sensor bulb for the water heater is ~$50. Any other things to check/try prior to just biting bullet and replacing it?

Thanks

IMO:

205 fahrenheit would be the max I would use.

BUT

You 'should' have a thermometer well and a good thermometer to actually KNOW the temp.



==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638