Alpine condensing boiler taking a long time to heat house.

Users who are viewing this thread

Thekid1

Member
Messages
69
Reaction score
2
Points
8
Location
Long Island, NY
Hey guys. I installed an 80kbtu Alpine(Burnham) 95% efficiency condensing natural gas boiler in my home back in 2015.

The home is roughly 1200sqft single story ranch with a full unfinished basement where boiler is located. Basement ceiling is not insulated. The windows upstairs are original.

So I get home about 8pm last night and my thermostat batteries died. I replace batteries and temperature in house is 60f. I set at 65 and took a shower. Now I know that probably stopped the boiler from heating house because I believe the indirect water heater is priority, but that shouldn't take that long to recoup, so I dont believe that was the issue. So go to sleep after about 830pm. I wake up at 430am and temp is at only 64f. I believe it was about 30f outside. Seems like a while to heat up right?

I noticed this happened last year too when the outside temperature was low, it seems like the boiler runs constantly and has a hard time keeping up, but I never noticed this since 2015 - 2018, but i could be wrong.

I know we can say the obvious is the basement ceiling not being insulated and maybe windows are outdated but I was thinking maybe because the boiler is so efficient, that its focused more on saving energy, than heating the house fast, maybe the temperature curve on the settings? But in worried if I mess with the settings, it will not be as efficient.

Last year when this was happening, I saw that the return temp on boiler was sufficient, I dont recall that temp, but my friend was walking me through it and said return temp was ok.

So what do you guys think? Is it bad to have the boiler run long periods of time like that?

The reason I never insulated it was because we go down there to do laundry and didnt want fiberglass floating around in the air. I looked into the denim/cotton insulation, but I've read it can harbor mold. I'm stuck on that issue so if anyone has any ideas, I'd appreciate it.
 
Last edited:

DIYorBust

Active Member
Messages
745
Reaction score
94
Points
28
Location
Long Island, New York
Long cycles is generally desirable on a condensing boiler, but if there has been a change in performance, I would definitely investigate that.
 

Fitter30

Well-Known Member
Messages
4,292
Reaction score
778
Points
113
Location
Peace valley missouri
What type heat emitters do you have? Radiate, radiators , fin tube? What water temp are you running? Thermostat that dies when the batteries go dead could be very expensive if it was 0* and you were gone for a day or more.
 

Thekid1

Member
Messages
69
Reaction score
2
Points
8
Location
Long Island, NY
What type heat emitters do you have? Radiate, radiators , fin tube? What water temp are you running? Thermostat that dies when the batteries go dead could be very expensive if it was 0* and you were gone for a day or more.

I'm running hydronic heat radiators. I guess its fintube. I'll check temp when I get home and report back. Yea the tstat is a cheapo depot one, but it did give me plenty of warning that it was low battery. It's a low voltage dual climate one, do they actually make ones that work on the low voltage without battery? I like the Nest, but too expensive for a tstat.
 

Thekid1

Member
Messages
69
Reaction score
2
Points
8
Location
Long Island, NY
Fin tube doesn't really start to heat below 120* water. Thermostat brand and model? System ave only the one zone?

So, the heat kicked on and I went down there and took a couple of pictures of the supply and return temps. The set point is 131F which isnt shown in the photos. Here are the photos. These numbers change within minutes with the boiler running and then slowing down. I was only down there for a 3-4 minutes and this is what I saw. Here are pics of the t-stat also. It's a Honeywell.
 

Attachments

  • 20201119_200827.jpg
    20201119_200827.jpg
    37.6 KB · Views: 198
  • 20201119_200817.jpg
    20201119_200817.jpg
    44.8 KB · Views: 206
  • 20201119_200753.jpg
    20201119_200753.jpg
    47.9 KB · Views: 195
  • 20201119_200739.jpg
    20201119_200739.jpg
    50.2 KB · Views: 189
  • 20201119_200649.jpg
    20201119_200649.jpg
    50.6 KB · Views: 181
  • 20201119_200544.jpg
    20201119_200544.jpg
    47.8 KB · Views: 188
  • 20201119_201318.jpg
    20201119_201318.jpg
    57.5 KB · Views: 202
  • 20201119_201308.jpg
    20201119_201308.jpg
    55.3 KB · Views: 196

Fitter30

Well-Known Member
Messages
4,292
Reaction score
778
Points
113
Location
Peace valley missouri
Take a few pics of pumps, boiler, piping and expansion tank. There is only one pic 139*-126* the others not moving enough water or boiler wasn't firing. Boilers usually run 10-20* temp difference between supply and return. Can't find any info on your honeywell stat except programing time of day.
 

Thekid1

Member
Messages
69
Reaction score
2
Points
8
Location
Long Island, NY
Take a few pics of pumps, boiler, piping and expansion tank. There is only one pic 139*-126* the others not moving enough water or boiler wasn't firing. Boilers usually run 10-20* temp difference between supply and return. Can't find any info on your honeywell stat except programing time of day.

The 5 pics I've posted last night were with the tstat calling for heat and were within a couple of minutes of eachother. It seems the boiler goes full blast, then slows down while tstat calls for heat, I assume that's why the numbers are all over the place.

The tstat is model: Honeywell rth2510b1018.

- The first pic below is with the tstat NOT calling for heat.
- The Tyco pump with silver label is for the 1 heating zone.
- The Tyco pump with the black label is for the indirect hotwater heater.
- The Grundfos pump is the main pump for the boiler. There is also a low, med, high setting and it's set on medium. The pump makes a little noise, dont know why.

Thank you for taking the time out for help with this, I know we all have our own lives. I really appreciate it.
 

Attachments

  • 20201120_074023.jpg
    20201120_074023.jpg
    36.6 KB · Views: 194
  • 20201120_074800.jpg
    20201120_074800.jpg
    65.7 KB · Views: 186
  • 20201120_075116.jpg
    20201120_075116.jpg
    47.9 KB · Views: 184
  • 20201120_075055.jpg
    20201120_075055.jpg
    63.8 KB · Views: 187
  • 20201120_074601.jpg
    20201120_074601.jpg
    89.9 KB · Views: 187
  • 20201120_074551.jpg
    20201120_074551.jpg
    84.4 KB · Views: 179
  • 20201120_074544.jpg
    20201120_074544.jpg
    80.2 KB · Views: 172
  • 20201120_074536.jpg
    20201120_074536.jpg
    83.4 KB · Views: 275
Last edited:

Fitter30

Well-Known Member
Messages
4,292
Reaction score
778
Points
113
Location
Peace valley missouri
Theres two stats one calls for boiler(heat) the other for the zone. The control for domestic hot water is from the storage tank to prioritize the boiler. Found a manual on your stat did you ever set up the heat cycle rate?
 

Thekid1

Member
Messages
69
Reaction score
2
Points
8
Location
Long Island, NY
Theres two stats one calls for boiler(heat) the other for the zone. The control for domestic hot water is from the storage tank to prioritize the boiler. Found a manual on your stat did you ever set up the heat cycle rate?

I believe you are correct, priority is the indirect hotwater heater. As for setting up a heat cycle rate, I dont think I had. Not sure what that is.

To answer DIYorBust's question, if by "outdoor reset" you are referring to the "outdoor thermometer", then yes, I have one installed.
 

Fitter30

Well-Known Member
Messages
4,292
Reaction score
778
Points
113
Location
Peace valley missouri
All thermostats have what used to be called a heat antisipator. If the stat was set at 70* boiler or furnace would come on at 68* but would shut off at 69* by the time unit would turn off it would be 71. This setting was adjustable. Heat cycle works about the same way. Do you only have the one stat? Not worried about outdoor reset yet. Does oiler pump and zone pump come.on at the same time or is their two stats in your living space. Heres a manual for your stat its a safe site use them all the time. Model of your boiler.
https://www.manualslib.com/download/1072917/Honeywell-Rth2510.html
 

Jadnashua

Retired Defense Industry Engineer xxx
Messages
32,770
Reaction score
1,190
Points
113
Location
New England
130-degree water in fin-tube is not going to radiate a lot of heat. Once the home is up to temperature, it might work to keep it there, but would be really poor at trying to raise a cold-soaked one to become warmer. To quickly warm the house, you'd need warmer water flowing through them, then to cool off once that load was achieved. I don't know what controls that boiler has, or how it works.
 

Thekid1

Member
Messages
69
Reaction score
2
Points
8
Location
Long Island, NY
All thermostats have what used to be called a heat antisipator. If the stat was set at 70* boiler or furnace would come on at 68* but would shut off at 69* by the time unit would turn off it would be 71. This setting was adjustable. Heat cycle works about the same way. Do you only have the one stat? Not worried about outdoor reset yet. Does oiler pump and zone pump come.on at the same time or is their two stats in your living space. Heres a manual for your stat its a safe site use them all the time. Model of your boiler.
https://www.manualslib.com/download/1072917/Honeywell-Rth2510.html

I only have 1 heating zone for living space and 1 tstat controlling it. The other zone is for the indirect hotwater heater.

Inside the boiler itself, all 3 pumps are connected to its board, meaning I dont have a separate "Tyco" control unit that controls extra zones(I forgot what they are called).

To answer your question, when the boiler kicks on to heat either the hotwater tank or the living space, yes, the boiler pump runs simultaneously.

I never set any "set point" temperatures on the boiler itself. It says it is set at 131F as per the photos. I think it was programmed like that from the factory.
 

Jadnashua

Retired Defense Industry Engineer xxx
Messages
32,770
Reaction score
1,190
Points
113
Location
New England
131F is enough (likely) keep the house warm once it gets there, but is nowhere near what it would take to reach the maximum output of the radiators you have if you're trying to raise the temperature. At that outlet temperature, you'll likely be reaching the stated efficiency as you'd end up with nearly full condensation of the exhaust which means you'd be transferring more energy to the home versus out the exhaust. Going from 130-degrees to say 180-degrees will more than double the output per foot of radiator and let you raise the temperature much faster. https://www.slantfin.com/images/stories/Technical-Literature/ratings_fineline30_r.pdf

A controller or setting, if it's available in your system, to raise the outlet temperature when it determines it needs more energy to do it would make things more comfortable, and do it faster, then, drop back once the setpoint is achieved to maximize efficiency. For best comfort, the system would be supplying just enough heat constantly to equal that lost to outside. That's hard to achieve, so the system will cycle, but it's more efficient and comfortable running constantly at just the right level, if possible.
 

DIYorBust

Active Member
Messages
745
Reaction score
94
Points
28
Location
Long Island, New York
130-degree water in fin-tube is not going to radiate a lot of heat. Once the home is up to temperature, it might work to keep it there, but would be really poor at trying to raise a cold-soaked one to become warmer. To quickly warm the house, you'd need warmer water flowing through them, then to cool off once that load was achieved. I don't know what controls that boiler has, or how it works.
This is where I'm thinking the outdoor reset settings could come in, but let's let fitter30 finish his initial troubleshooting. I had a similar issue once where I had an outdoor reset, and a taco relay. The plumber set it up where the water heater aquastat called for heat through the relay's priority terminal. However the boiler never knew if it was being called for heat or hot water, so it was making hot water with only 130 degree water which was significantly increasing the recovery time.

However in a space heating situation, having a long cycle at a low temperature is actually the goal. If the home can be heated with 130 degree water, condensing can be maximized and fuel use can be reduced.
 

Fitter30

Well-Known Member
Messages
4,292
Reaction score
778
Points
113
Location
Peace valley missouri
Here the manual if you don't have one. This web site i use all the time. Starting at page 101 shows service settings. From outdoor reset to boost time.
https://www.manualslib.com/download/689025/Burnham-Alpine.html
My concern is the only one pic that showed 23* them difference. The others 1* difference. At 1* either the boiler is off and or system pump is off. 23* the boiler is working. At the 1* difference is there a temp difference before and after the two tees than the boiler ties into system piping?
 

Jadnashua

Retired Defense Industry Engineer xxx
Messages
32,770
Reaction score
1,190
Points
113
Location
New England
If I understand outdoor reset controls, they adjust the boiler temperature based on the outside temp...the colder it is outside, the hotter it makes the water. In the case of reheating the home from what amounts to a setback (unintended in this case), seeing that it was mild, it would have no reason to raise the boiler setpoint unless it was smarter.

A design that looked at the return water temp if available, that could then decide the supply temp would need to be raised to achieve the thermostat demand quicker when the delta was high.
 

Thekid1

Member
Messages
69
Reaction score
2
Points
8
Location
Long Island, NY
At the 1* difference is there a temp difference before and after the two tees than the boiler ties into system piping?

I really dont know how to find this out to answer your question.

You know what, maybe I should see if I can shoot a video of the screen on the boiler when it calls for heat so you can see how the boiler fires during the process.

Other than that, I believe the tstat I have is a piece of crap. On page 94 of the manual, it talks about "EnviraCOM enabled tstat". I dont believe my tstat has that. Could this be the issue maybe? See below:

"Setback” Setpoints User adjustable setback setpoints are provided for both Central Heat and DHW demands. The Setback setpoint is used when the EnviraCOM thermostat is in “leave” or “sleep” modes. When setback is “on” the thermostat setback setpoint shifts the reset curve to save energy while the home is in reduced room temperature mode. The Honeywell VisionPro IAQ (part number TH9421C1004) is a “setback” EnviraCOM enabled thermostat."
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks