Understanding Cold Issue

[RetiredMT]

I have a Lochinvar Model WHB-155N Series 100 boiler. It and the house is 3 years old. I live in the mountains in Montana where the winters are long and cold. Season 1 the boiler worked perfectly. 2 and 3 there are issues and I've basically replaced everything inside (gas valve, computer boards, fan motor, etc.) Now what's happening is when it's EXTREMELY cold outside (-15 F and below), the boiler appears to be struggling. When all zones are calling for heat, the boiler does not go into high fire mode. I've talked with Lochinvar tech support and based on the numbers I give them, they say the boiler is operating the way it's programmed. Can anyone help me? TIA

Also, getting a tech where I live is really difficult and I've already spent $1500 on repairs.

 

[Breplum]

try HeatingHelp The Wall website.
Nobody really will be able to help who is not an experienced expert.

 

[Sponsor]

 

[Fitter30]

What are your water temps, heat emitters ? In and out of the boiler?

 

[RetiredMT]

What are your water temps, heat emitters ? In and out of the boiler?

I know this might not exactly answer your questions, but this boiler works perfectly until the outdoor temperatures get super cold. Then as the house starts to cool off and all zones call for heat, the %flame never goes over 35% and the outgoing temperature of the water is no greater than 90F. I was wondering if the outside sensor would have something to do with this? Not sure.

 

[Fitter30]

What size is your lp tank and is it above ground? Lp tanks have a vaporization amount of flow based on temp and level in it. Hers a chart for 500 & 1000 gallon

https://www.google.com/url?q=https://babfar.com/wp-content/uploads/2016/12/BABFAR-Vaporization-Tables.pdf&sa=U&ved=2ahUKEwiJ2bWc_6P8AhXAGDQIHbJPDDcQFnoECAsQAg&usg=AOvVaw0IQgnkCupw2ekwg-RMm5r2

Here's the manual page 73 has outdoor temp

https://www.google.com/url?q=https://www.lochinvar.com/lit/100305186_2000558066_Rev%2520H_WHB%2520I%2526O_(51638).pdf&sa=U&ved=2ahUKEwj6jbm2n6T8AhUgAzQIHchECCcQFnoECAUQAg&usg=AOvVaw2MCmDokBx4NuWF8YVYY0-l

Service manual page 23 outdoor reset

https://www.google.com/url?q=https://www.lochinvar.com/lit/KB-SER-08.pdf&sa=U&ved=2ahUKEwjSi_7WoKT8AhV7ADQIHUbKCAMQFnoECAQQAg&usg=AOvVaw0RnTg_S5aY33CEURAlPQaU

 

[RetiredMT]

What size is your lp tank and is it above ground? Lp tanks have a vaporization amount of flow based on temp and level in it. Hers a chart for 500 & 1000 gallon

https://www.google.com/url?q=https://babfar.com/wp-content/uploads/2016/12/BABFAR-Vaporization-Tables.pdf&sa=U&ved=2ahUKEwiJ2bWc_6P8AhXAGDQIHbJPDDcQFnoECAsQAg&usg=AOvVaw0IQgnkCupw2ekwg-RMm5r2

Here's the manual page 73 has outdoor temp

https://www.google.com/url?q=https://www.lochinvar.com/lit/100305186_2000558066_Rev%2520H_WHB%2520I%2526O_(51638).pdf&sa=U&ved=2ahUKEwj6jbm2n6T8AhUgAzQIHchECCcQFnoECAUQAg&usg=AOvVaw2MCmDokBx4NuWF8YVYY0-l

Service manual page 23 outdoor reset

https://www.google.com/url?q=https://www.lochinvar.com/lit/KB-SER-08.pdf&sa=U&ved=2ahUKEwjSi_7WoKT8AhV7ADQIHUbKCAMQFnoECAQQAg&usg=AOvVaw0RnTg_S5aY33CEURAlPQaU

lp tank is 1000 gal and is below ground. Propane works fine since we also have 2 gas fireplaces. Is it possible that outside air can be TOO cold?

 

[Fitter30]

Outdoor sensor can be seen on screen page 73 install manual. Sensor goes to -50°
Also look at outdoor parameters or turn it off. Just set a temperature. Might just check incoming gas pressure need 11"
Piping from tank regulator at tank ( tank to 10lbs)
Regulator at house 10 lbs to (11 - 12")
Looked at specs on a Emerson reg operating temp to -20° look at the specs.

 

[Dustbunny]

My oil fired boiler doesn't seem to have a stated minimum operating temp. listed. Last winter ( it's first year in a 1990 house) , it would not fire off when the outside temp was below zero. Nothing particular seemed to solve it after it happened 3 times.

This winter, I plan on disconnecting and capping the outside air intake when it will be below zero and see if cold intake air is the problem or if it's something to do with chimney/draft.

 

[Fitter30]

Boiler get serviced once a year? Do they use a flue analyzer ? Heating oil freezes at 16°. Outside air open all time or does it have a motorized damper?

 

[RetiredMT]

Boiler get serviced once a year? Do they use a flue analyzer ? Heating oil freezes at 16°. Outside air open all time or does it have a motorized damper?

Yes it's service annually. However everything is practically new since May of '22. Yes outside air is open all of the time because this boiler also services our hot water. Our house has in floor radiant heat throughout the house and garage. Yes an analyzer is used and everything is within spec.