Pentair Mastertemp 400 LPG high pitch squeal possibly low pressure

[Jmotley0104]

Good evening and first post! After a year construction and waiting I was finally able to fire up my pool and spa heater. During operation my Mastertemp 400 makes a high pitched squeal. I did some googling and it sounds like it may be caused by low pressure. I have a 500 gallon buried propane tank that is managed by the gas company. My question is do they make adjustments to the gas pressure? I found this diagram in the manual and just want to make sure that is something they adjust before I give them a call or should I call pentair for warranty?
Thank you in advance!
Jason

 

[Poolbreh]

Hi and welcome,It sounds like an orifice
Problem. Are you sure the heater is propane and not natural gas?

 

[Jmotley0104]

Hi and welcome,It sounds like an orifice
Problem. Are you sure the heater is propane and not natural gas

Hi and welcome,It sounds like an orifice
Problem. Are you sure the heater is propane and not natural gas?

The pentair p/n number is 460736 which I believe works with propane as well. The manual lists both hopefully I'm not wrong on that statement though. I'm sure I have propane and not natural gas in my tank though.
Thanks!

 

[Poolbreh]

The orifice sizes are different between LP and NAT. If it’s the wrong type it usually gives a squeal when fired up. I would confirm heater type. Installing the wrong type does happen. I don’t think that part number distinguishes what type unless there is a LP or NA at the end.

 

[Poolbreh]

 

[Jmotley0104]

Wow so I have NA at the end. See attached screenshot. Are you saying that they installed the wrong fuel type heater or potentially the wrong orifice? I hope that's not what you are saying . It also makes the noise the whole time it runs just not at start up if that makes a difference.
Much appreciated!

 

[Poolbreh]

Correct. I would see if the PB can come out and change the orifice.

 

[Jmotley0104]

Correct. I would see if the PB can come out and change the orifice.

Thanks I called said he doesn't think they installed the conversion kit. Hopefully that resolves the issue. I'll keep you posted!

 

[Jmotley0104]

Correct. I would see if the PB can come out and change the orifice.

Update I replaced the orifice to the propane one and no more high pithed squeal! Issue I am having now is the heater will fire up and run for about 30 seconds then shuts off. Then it will run again a bit later then shuts off. Its like it is cycling on and off. I have called the PB but am waiting on a response. Any thoughts or is the heater cycling normal? I have the temp set to max on the master temp as well as what I have the easy touch set to. But in a 20 min time frame the temp rose 2 degrees.

 

[Toxophilite]

The pentair p/n number is 460736 which I believe works with propane as well. The manual lists both hopefully I'm not wrong on that statement though. I'm sure I have propane and not natural gas in my tank though.
Thanks!

It would have come NG and needed orifice changed if on Propane.

 

[Jmotley0104]

It would have come NG and needed orifice changed if on Propane.

Correct I changed the orifice to propane but the heater runs for about 30 seconds then shuts off. Then back on about a minute later then back off. This unit was brand new about 3 months ago. The pool was just finished and I was turning on for the first time. Do I need to change anything else other than orifice as it initially ran longer than it does now though it had the squeal.

 

[Jmotley0104]

It's running 30 seconds on 30 seconds off. Rinse and repeat.

 

[1poolman1]

No error codes. Unusual noises (banging, rattles)?

 

[Jmotley0104]

No error codes. Unusual noises (banging, rattles)?

Correct no banging or error codes. The flashing light goes solid while it's running for 30 seconds and then back to flashing after I hear the burner turn off.

 

[Jmotley0104]

I placed the old natural gas orifice on and it runs non stop just has the squeal.

 

[Turbo1Ton]

Did you ever have anyone confirm the gas pressure at the inlet, as well as on the gas manifold in the heater?

Sounds as if you may be losing gas pressure. It runs for 30 seconds, gas pressure drops, shuts off because no/weak flame, pressure builds back up while its off for the 30 seconds, rinse and repeat. The larger orifice allows enough flow to overcome the low pressure.

What is the LED on the Fenwal doing when this happens?

--Jeff

 

[Jmotley0104]

Did you ever have anyone confirm the gas pressure at the inlet, as well as on the gas manifold in the heater?

Sounds as if you may be losing gas pressure. It runs for 30 seconds, gas pressure drops, shuts off because no/weak flame, pressure builds back up while its off for the 30 seconds, rinse and repeat. The larger orifice allows enough flow to overcome the low pressure.

What is the LED on the Fenwal doing when this happens?

--Jeff

That has not been done yet. So far I was told to have the gas company turn on the gas and that was it. I have one of the pbs coming tomorrow hopefully that is something that they can check. I'm attaching the two vids of what the light is doing while it's running and when it's not.
Cycling
Running

 

[Poolbreh]

I would confirm the orifice size. They differ in size based on btus.

 

[Jmotley0104]

I would confirm the orifice size. They differ in size based on btus.

I am using part 77707-1441 which is .322" which seems to be the propane orifice for the master temp 400.

 

[Poolbreh]

That is the correct propane orifice for a 400btu. If it works with NAT orifice I would imagine gas pressure is fine because the WC is equivalent. Let’s see what @ajw22 says.