Brand new Pentair MasterTemp 250 LP won't ignite

JamesW

TFP Expert
Mar 2, 2011
20,294
At this point, we know for sure that the gas supply isn't right.

Until the gas supply is done correctly, I don't think that it makes much sense to start chasing down heater defects.

The orifice kit part number for the 250,000 btu/hr propane is 460740.

The brass orifice is stamped with two letters to indicate the btu/hr rating and the type of gas.

The type of gas is either N for natural or L for liquid propane.

I think the correct letters for the 250,000 btu/hr propane heater are "S L".
 

Martian

Member
May 17, 2020
15
Ecuador
The name of the heater is MasterTemp LP
It cannot be a natural gas heater. Propane contains more than twice the energy of natural gas. So natural gas version must supply more gas to get it ignited.
I think in my case I have to get natural gas one connected to propane.
One cubic foot of propane = 2,516 BTUs compared to one cubic foot of natural gas = 1,030 BTUs. Propane contains more than twice the energy of natural gas. In one hour, a 100,000 BTU natural gas furnace burns around 97 cubic feet while a propane furnace burns only 40 cubic feet in an hour.
And yes the only difference between LP and natural gas versions is just orifice.
 
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JamesW

TFP Expert
Mar 2, 2011
20,294
The name of the heater is MasterTemp LP
The SL is what should be stamped on the gas orifice. PC was speculating that the gas orifice might be incorrect. You can check it if you want, but I suspect that the heater will work correctly once you get the gas supply right.
 

JamesW

TFP Expert
Mar 2, 2011
20,294
I think in my case I have to get natural gas one connected to propane.
You're just randomly trying different things with no specific logic.

You just need to get the right gas supply as specified.

Maybe call Pentair for help or a local gas contractor.
 

Martian

Member
May 17, 2020
15
Ecuador
You're just randomly trying different things with no specific logic.

You just need to get the right gas supply as specified.

Maybe call Pentair for help or a local gas contractor
Randomly? Not actually. I found my gas pressure is not enough but if I install more powerful regulator I get too much pressure and Pentair inlet valve blocks it. And I confirmed it partially covering air inlet.

As I said I'm not in US and there is NO Pentair and NO qualified gas contractor, just gas bottles. And this is why I opened this thread. But looks like there is no people here who knows and able to help. You cannot even suggest me a regulator so I'm studying myself.
 

JamesW

TFP Expert
Mar 2, 2011
20,294
Ok, I can appreciate that you don't have the access to resources that might be available in other places.

Sorry that we can't be more helpful.

Good luck and let us know how it goes.