MasterTemp 400 problems

[Sws]

Thanks. I’ll say it’s with everything running that would run while the pool heater is running. The gas furnace obviously only runs in winter as does the gas fire place.

So it lines up well between 4 and 14. Is there another place to test the manifold pressure (or is that change in pressure?)

If you measured it with everything off, that's static pressure and doesn't tell the story. With everything running, it could be sucking the line down and causing a pressure drop.

We need to know what it is under load. That's basically the smallest meter available and is definitely choking your gas system. You should have the utility involved in this but don't expect them to leave the heater connected.

Im not saying your existing meter won't work in the short term, but I am saying that that meter isn't sufficient for your heater at all and will be problematic. Its only rated to support a 250 load at 7" and you're over that with just the heater.

You should probably have a 1 1/4 gas line to it also.

 

[Charleswwelch]

If you measured it with everything off, that's static pressure and doesn't tell the story. With everything running, it could be sucking the line down and causing a pressure drop.

We need to know what it is under load. That's basically the smallest meter available and is definitely choking your gas system. You should have the utility involved in this but don't expect them to leave the heater connected.

Im not saying your existing meter won't work in the short term, but I am saying that that meter isn't sufficient for your heater at all and will be problematic. Its only rated to support a 250 load at 7" and you're over that with just the heater.

You should probably have a 1 1/4 gas line to it also.

Ok. I hear you guys and Sws drove it home. I will definitely look at having a new meter put in and plan to have some plumbing work done after they replace it. Especially since I’ve considered outdoor gas logs in the past which would be running sometimes when the pool heater is. But, since I have sufficient static pressure and the back firing is occurring when nothing else is running, I guess I have one immediate problem and one long term. If you mean I need to test it while the heater is firing I can but it literally never fully ignites this year and last summer it lit up every time without issue. The video was showing the gas pressure drop when the control board called for gas, I just unplugged the igniter. How can I get the heater going for now while I work on the gas company/new meter? Otherwise without the heater, there’s no point in the new meter.

 

[Charleswwelch]

That is your problem.

You need a minimum of 4" WC.

While you have good static gas pressure, your meter and pipe cannot give the sustained gas flow between 4 and 14 WC the heater needs.

Thanks. I see this response now. I missed it earlier as the latest post was pushed to another page. So, I'm calling the gas co tomorrow to replace the meter. Sounds like I'll need to have the heater line tied back in by someone other than the gas company. Is there anything I should note for the gas company to increase my chances of getting 4" wc through the existing 1 inch line with the new meter? It had to have been at that level through the existing line at some point to work last year, right? Thanks again all. I'll be back again once I get the utility out, hopefully this year sometime.

 

[Sws]

Thanks. I see this response now. I missed it earlier as the latest post was pushed to another page. So, I'm calling the gas co tomorrow to replace the meter. Sounds like I'll need to have the heater line tied back in by someone other than the gas company. Is there anything I should note for the gas company to increase my chances of getting 4" wc through the existing 1 inch line with the new meter? It had to have been at that level through the existing line at some point to work last year, right? Thanks again all. I'll be back again once I get the utility out, hopefully this year sometime.

You may get away with the 1 inch.

Id expect them to change the regulator to something 1 1/4. The rest of the load will determine what meter you will need. Its easy to exceed even a 630 when you are using 400 just for the pool heater. A 630 install can be done with an 1 1/4 meter bar. Anything bigger is a custom plumbers header.

Where im from, the gas company could supply up to 9" max WC as long as the dynamic pressure doesn't drop below 7. Yours could be different so this is really a conversation for your plumber and them.