Mastertemp 400 now will l not heat

sgterik

Active member
Mar 31, 2020
33
Arizona
So I am trying to figure out my heater which keeps throwing a "Service System" error. I checked and it is the "PS" which I know is the Pressure Switch. I checked and it was not working properly so I was able to fix the switch and it pops up now and engages. But I still got the error. So I bypassed the switch and closed the circuit. Same "PS" Now here is where it is weird. If I open the HLS circuit with the PS circuit closed the HLS light turns on, but if i close the HLS circuit the PS lights back up. What do you think I should try next?
 
Welcome to TFP.

Check if rats got into the heater and chewed on some wires.
 

Enjoying this content?

Support TFP with a donation.

Give Support
I purchased it used off craigslist and it looked almost new. Date shows 1/08/2014.. I paid like $300 which was a steal but had to replace the gas regulator and that was a few hundred dollars. After that it worked great. Hadnt used it in a few months due to my pool sitting at 88 degrees without. I just replaced the board and when started up all before issues seem to be gone. New board is a bit different but it is the newest one pentair said to use. When started the "Service Heater" comes on for a second or two then goes away and the "Heating" goes solid then after a bit it blinks, then solid. Blower comes on but I am not getting heat. Then after a bit the "Service Heater" comes on and stays on. So I am thinking gas regulator or ignitor maybe now?
 
So Solved the issue earlier of error lights. Just put in new board. Heater starts up, no errors. Although when initially powered on the "Service Heater" light comes on for a second or two then goes away. Blower comes on and "Heating" LED is solid. Then nothing, after a few seconds the "Heating" led Blinks, then Solid for a bit, then blinks. Blower keeps going and after a bit the "Service Heater" LED comes on and no error codes or light on back. Heater is from 2014. Bought used this past spring and put in a brand new Gas regulator. Worked fine before summer.
 
Blower goes on but do you hear ignition and get any heat exhaust before it shuts down?
 

Enjoying this content?

Support TFP with a donation.

Give Support
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.