Pressure required for Pentair 400K BTU heater.

Manny123

I'm caught up in a nightmare of a situation with pool heater technivian pointing at gas line issue and gas company pointing finger at pool heater. I had a StaRite Max E therm 400K btu heater which stopped working around the time my gas meter got upgraded 2.5 psi 800 cfh. My pool technician said it was my gas line so I had gas company come by and measure pressures before and after the regulator and near inlet to my heater which was 8.3 to 8.6 iwc. He said it was sufficient. I decided to get second opinion on heater and new heater technician said it was probably the heater. I replaced the heater with a 400k BTU mastertemp and it's still not working and now he's blaming the gas line. I have a gas company appointment in about a week and trying to figure out what I need him to check. I'm at wits end and feel like I just spend $4K on a new heater that I didn't need. At this point I just want it to work. Also since people will ask, I have a 2" pipe from regulator to the heater, about 100 ft run. I really appreciate any advice!

EBEBRATT-Ed

Your 2" pipe is large enough. You need to get the gas company and service tech onsite at the same time if possible, Hook gauges to it everywhere and measure gas pressure while starting and running.

Have you contacted the gas co engineering dept? This should have been done before the install.

What's your location?

Manny123

Thanks for the reply and advice about getting the gas company at the pool heater technician there at the same time. I did not contact the wmgineering department but I had the same exact heater there before. 400K btu Sta Rite and now I have the 400K btu Pentair Mastertemp. From what I understand it's the same heater. I'm located in Los Angeles 90036

EBEBRATT-Ed

Did the original heater work without any issues?

TAG

Does the heater company publish a min needed ..... try and call them and ask for technical.

What stopped working with the old one? normally they leak or some sensor fails

Ironman

When the service was changed to 2psi, was a step down regulator installed near the heater?

Ironman

Disregard my last post. I see that you said that pressure was read near the heater at 8.6” WC. That should be more than sufficient if this is on natural gas.

That was probably also at a static reading. An active reading should also be taken while the heater is trying to ignite to confirm sufficient pressure when there’s a high volume of gas passing through. Under a high volume, there may be a large pressure drop which could prevent the heater from firing.

There could also be another unrelated issue with the new heater while everyone is fixated on the gas line.

Manny123

EBEBRATT-Ed said:

Did the original heater work without any issues?

Original heater worked fine before. Gas meter was changed in the winter time so I did not use the heater for a while and when I tried firing up for the season it stopped working. 

Manny123

TAG said:

Does the heater company publish a min needed ..... try and call them and ask for technical. What stopped working with the old one? normally they leak or some sensor fails

It would fire and then go off. Seemed like a pressure drop after firing caused it to stop. Unfortunately, gas company tech everything was fine with the line based on his measurements and based on calculations meter is big enough, pipe big enough, etc... So I replaced heater. Same issue with gas line now. 

Manny123

Ironman said:

Disregard my last post. I see that you said that pressure was read near the heater at 8.6” WC. That should be more than sufficient if this is on natural gas.

That was probably also at a static reading. An active reading should also be taken while the heater is trying to ignite to confirm sufficient pressure when there’s a high volume of gas passing through. Under a high volume, there may be a large pressure drop which could prevent the heater from firing.

There could also be another unrelated issue with the new heater while everyone is fixated on the gas line.

Going to try to have gas tech and pool tech there together at same time. 

mattmia2

Did the gas tech try to fire it? Does it fire at all? if so for how long?

GGross

The gas pressure reading they took while nothing was firing (static gas pressure) is only one of the numbers they need. The gas company and your contractor should know this, but if they don't just make sure they test it more thoroughly. Static pressure, running pressure, high lockup, and check with every appliance attached to the same service running.

EBEBRATT-Ed

This should not be a difficult problem to solve. Too bad you probably bought a new heater you didn't need. I would lean on the gas company hard and insist they get their best tech on the job

Jamie Hall

EBEBRATT-Ed said:

This should not be a difficult problem to solve. Too bad you probably bought a new heater you didn't need. I would lean on the gas company hard and insist they get their best tech on the job

GGross said:

The gas pressure reading they took while nothing was firing (static gas pressure) is only one of the numbers they need. The gas company and your contractor should know this, but if they don't just make sure they test it more thoroughly. Static pressure, running pressure, high lockup, and check with every appliance attached to the same service running.

Check also for dips in pressure when other appliances turn on or off (or this one, for that matter). If the pressure drops too low (or too high, but that's rarer) even for a few moments, the gas valve is supposed to lock out. Some are more sensitive than others.

Zman

Have your gas tech check the pressure at the meter (or step down regulator) with all appliances running. If it drops below 7" WC it is the gas company's issue to resolve.

Then check the pressure at the pool heater with all appliances running. If it drops below 7" WC it is your issue to resolve.

If it does not drop below 7" WC in either test, you do not have a gas pressure issue.