Pentair 250 heater problems

Jvrpants

Member
Oct 17, 2020
15
Florida
Needing some help with my pool heater. We recently had to change the membrane pad and the transformer and now the machine turns on its own when we plug the power back on. The Pad does not turn it off and the heater does not even light the propane. I unplugged the membrane pad and it continued to do the same thing. Can anyone help me out here?

Thank you for your time.
 
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To start with it would be useful to know why both the membrane pad and the transformer were replaced. For example, transformer secondary open or transformer visibly burnt and membrane pad blank or non responsive etc. ? Obviously the replacement membrane pad would be OEM ( Original Equipment Manufactured [Pentair]). Was the transformer also OEM? What is the supply voltage that the heater is using? The OEM transformer is listed as using either 115V or 230V on the primary side. Was the new transformer wired correctly to the supply voltage? What were the original symptoms when the heater was not working? When you say the heater tries to run with no input from the membrane pad, I am assuming that you mean that the combustion blowers runs with no observable input from the pad? This should be the manual for your heater https://images.inyopools.com/cloud/documents/pentair-heater-mastertemp.pdf The wiring diagram and ladder diagram are on pages 36 and37.
 
To start with it would be useful to know why both the membrane pad and the transformer were replaced. For example, transformer secondary open or transformer visibly burnt and membrane pad blank or non responsive etc. ? Obviously the replacement membrane pad would be OEM ( Original Equipment Manufactured [Pentair]). Was the transformer also OEM? What is the supply voltage that the heater is using? The OEM transformer is listed as using either 115V or 230V on the primary side. Was the new transformer wired correctly to the supply voltage? What were the original symptoms when the heater was not working? When you say the heater tries to run with no input from the membrane pad, I am assuming that you mean that the combustion blowers runs with no observable input from the pad? This should be the manual for your heater https://images.inyopools.com/cloud/documents/pentair-heater-mastertemp.pdf The wiring diagram and ladder diagram are on pages 36 and37.

Hello there, sorry for the late response. I have not been able to go to the home that has the heater for quite some time to check on things but now I do have time. We first changed the pad because water had gotten into it and one of the buttons were completely damaged and the new pad we put now is original. We recently found out that the transformer that was placed there to replace the old one was the incorrect one and we ordered the correct piece using the model number given to us by Pentair. Actually the old transformer that we had to replace was not an OEM but the heater was working just fine before all this happened. The current symptoms of the heater are that the new pad is unresponsive and the heater does turn on when given power and it does ignite the propane but we are not able to control the temperature nor are we able to turn it off by pressing the buttons. The only way to turn it off is from the breaker. Is it possible with this incorrect transformer that the pad will be unresponsive? What are the chances that the circuit board is affected?

Thank you for your time.
 
Am I to understand that you are the heater repair tech rather than the pool owner? You still haven't stated what the problem was with the transformer. The transformer does not really need to be OEM as long as the input and output voltages and VA rating are the same. For electrical troubleshooting refer to pages 36 & 37 of the Pentair manual.
 
Recently we had to change the membrane pad and transformer on our pentair 250 and after we did so it began to work normally. We have two regulators on the gas line, 1 that is near the propane tank and the secondary that has a shut off valve near the heater. Now when we turn on the heater and open the gas line and secondary regulator the heater does not ignite. We hear the clicks when it tries to ignite but we do not smell any gas coming from the exhaust. The first time when we noticed this we saw propane coming out of the vent of the first regulator and we shut off the heater and the gas. This did not occur again the second time we tried the heater but it still does not ignite and we do not smell gas coming from the exhaust. Can anyone help?

I hope I explained myself enough. Any help will be greatly appreciated.
 
It seems that you are posting under 2 separate threads ( "Pentair 250 heater problems" 10/17, 10/18 and 10/29 ). Now "Pentair 250 won't ignite" 11/11. It also seems that you are the repair technician rather than the pool owner re: posts on 10/29. It is difficult to be of any help if you don't answer all questions that are asked re: posts on 10/29.
 

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I wish I was a repair a technician because if I was I would not be posting messages on here. I am a pool owner and the heater is at a vacation rental and I do not always have access to the home when it is rented. We were able to get the heater running properly the last time by putting 115/230 dual voltage transformer and it did work at the time. Now our issue seems something unrelated to our original one. Additionally there are no error codes showing up on the panel.
 
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Here are some pictures and yes we were able to get it running like normal with replacing the transformer. The red regulator is a Emerson-Fisher regulator and that belongs to the gas company. The secondary green regulator is a sherwood. We had a tech come by today to do a free check up and estimate and he said he thinks it is either our regulator or the ignitor. He also mentioned that he did not smell gas come out from the heater when he heard it click. Is there a way to test the regulator to see if it is bad?
 

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The regulator, gas valve and ignitor can all be tested with common tools that every service technician should have E.g. , multimeter and manometer. Questions that should be asked. Do you have ~ 11.0 to 13.0 inches WC propane pressure at the inlet of the gas valve? Do you have 24 VAC at the gas valve when the heater is calling for heat? Is the gas valve opening when you have 24 VAC applied? Does the propane supply pressure drop too low when the gas valve opens? Can't understand the techs inability to isolate either regulator or ignitor as the source of the problem as the ignitor can be checked by reading ohms of resistance and supply voltage on a call for heat and the regulator can be checked with a manometer??? When checking the gas valve outlet pressure to the gas manifold, instructions in the heater manual should be closely followed as this is a negative pressure gas valve coupled with a "combustion" blower rather than a positive pressure gas valve coupled with "draft inducer" blower.
 
We were able to measure the Ohms of resistance on the ignitor and it was good. We do not have a manometer at the inlet of the gas valve. We measured the voltage of the gas valve and there was 24 VAC when being called for heat on the left side of the "on/off switch. On the right side of the switch there was no 24 VAC when calling for heat and we are thinking that the valve is not opening due to no power reaching it and that is probably why we do not smell gas coming out of the stack flue when we turn on the machine and it tries to ignite. Do you think that might be it?
 
. We measured the voltage of the gas valve and there was 24 VAC when being called for heat on the left side of the "on/off switch. On the right side of the switch there was no 24 VAC when calling for heat and we are thinking that the valve is not opening due to no power reaching it and that is probably why we do not smell gas coming out of the stack flue when we turn on the machine and it tries to ignite. Do you think that might be it?

Pentair_MasterTemp_Gas_Control_Valve.jpg


Is the ON/OFF switch ON?

Test if the switch is defective. Bypass the switch and connect the wires on the right and left of the switch directly. Plug the right side gas valve wires directly into the TH and TR block behind the gas valve.
 
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Pentair_MasterTemp_Gas_Control_Valve.jpg


Is the ON/OFF switch ON?

Test if the switch is defective. Bypass the switch and connect the wires on the right and left of the switch directly. Plug the right side gas valve wires directly into the TH and TR block behind the gas valve.

It is most definitely on. We trie it and the gas valve made a repeated clicking sound when called for heat then stopped and it did not ignite.
 
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Sounds like a gas valve or gas supply problem.
 
So we opened part of the gas valve where the electro magnet is and we moved the plunger in there up and down and it does move and looks clean. We then connected the electric magnet directly to TH and TR the magnet was functioning and picking up the plunger when being called for heat. The on and off switch may be bad.
 
Are you sure you have gas at the heater? We had one member who ran after all sorts of problems in his heater until he found that the gauge on his propane tank was broken and was reading half full when it was empty.
 

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