Garage Furnace issues

[hbar218]

The thing with a reznor is its rated to 0-2000ft elevation. The mr heaters are rated for high elevation, at least the older canadian mr heaters we good to 2000-4500ft.

So when purchasing a reznor the output will need to be derated for the altitude, if its over 2000ft.

Its easy to derate, the gas pressure just needs to be set to 2.8”wc for natural gas. Even if the Mr. Heater ones are “ rated” for high altitude they still need gas pressure checked and probably adjusted.

 

[hbar218]

Looking for anyone who may know someone or a company that can give me a quote for a new garage furnace. Had a technician diagnose problem yesterday as either a weak purge motor or weak pressure switch. He is checking into parts but I don't feel confident he will have any luck. I really didn't like the ballpark quote he gave for $2500-3500. thx

Unless you have and old and obsolete , which i doubt because it wouldn’t have combustion motor and pressure switches, or else an off brand , parts should be readily available. I would think it would be $1500-$2000 to replace it unless you need to upgrade to stainless venting which is an extra few hundred $.

 

[Caper11]

Its easy to derate, the gas pressure just needs to be set to 2.8”wc for natural gas. Even if the Mr. Heater ones are “ rated” for high altitude they still need gas pressure checked and probably adjusted.

Yes that right the pressure should be checked.
But Not what I ment. A resnor 45000btu would be derated to 41000btu, this is an example.

The Canadian mr heater units are rated as per their nameplate.

So if a person was looking at a resnor he would need to look at a higher btu unit to compensate for the loss at altitude. Most of your appliances in your house are rated for 4500ft.


My furnace and my water heater are rated for a altitude of 0-4500ft.

My broiler on the other hand is not. So its output was derated from 42000btu, to 37000btu.