Converting LP heater to Natural Gas

Dec 12, 2009
10
How difficult is it to convert a Minimax 400 from LP to natural gas? We are switching the entire house over from lp to natural gas and cannot find anyone in Montgomery, Texas, area to discuss the pool heater conversion with. Thanks.
 
Re: New pool owner with questions

In most cases, I think it can be done by simply replacing the orifice (your local gas dealer can explain) I think there might be some instances where the pressure regulator requires adjustment but I can't remember.

We cook with LP and I ordered a new cookstove online that was set up for natural gas. To the best of my knowledge, I simply changed the orifices and it was all set for propane.
 
Re: Converting pool heater from lp to natural gas

Conversion from LP to natural gas on any type of burner is a simple matter of changing out the jet that aeroselizes in the gas. LP vs natural gas are different sizes. Check with Pentair. It should be an easy change out.
 
Re: Converting pool heater from lp to natural gas

Welcome to TFP to the both of you!!

I've worked extensively with Max- E - Therm heaters and, with those, it's a simple change in the brass orifice in the in fluent line to convert from NG to LP :)

No other change is required other than the orifice on the line coming into the 'block' :cool:
 
I spoke to a Pentair rep. about this before and he said that you cannot switch from propane to natural with the older style heaters. According to him, the natural gas heater is a sealed combustion chamber and the propane heater is not. With the new Mastertemps and Max-e-therms it is as simple as changing out the orfices but not with the TSI's or NT's.
 
Thanks for the various tips. I appreciate them all. Is there a designation in the model or serial number that identifies the type of 400 I have? Best guess is that the unit is 8 or 9 years old as it was installed during the constructon of the house. Appreciate the help. Like this site a lot.
 
Scott: I do not believe it has a fan. I can see the tubes ignite when I take the front cover off and look up into the burner area. Beginning to wonder if maybe I should just buy a 20 gal lp tank and skip the conversion of this item from lp to natural. What do you think?
 

Enjoying this content?

Support TFP with a donation.

Give Support
You would know if you had a fan start before the heater fired. As such, what PoolClown said earlier is correct. The orifices for the burners and the gas block regulator would need to be changed. It is not something I reccommend a homeowner do.

A 20 Lb tank isn't big enough. If it could be hooked up, it would last only a couple hours. How big is the existing tank(s)? My 300K unit burns several GPH. When the heater dies, then do the switch to an NG heater.

Scott
PoolGuyNJ
 
HI, hope I'm not thread stealing here, but I have pretty much the same question about a pool heater. We set up our 33ft AGP this past fall and the only thing I didn't get finished was to plumb the gas to the heater. Our heater is also a propane heater, and I'd like to switch it over to Natural gas. It is the Hayward H200 series (200,000 btu's)

If anyone could give me info on switching this from propane to natural gas, that would be great. I do understand a different orifice will be needed, but what about the valve? I know gas works on pressue, and propane is high pressure, while natural gas is low pressure.

Any help would be great.

Thanks
Dan
 
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.