Master temp 125

UKjames

Silver Supporter
May 1, 2020
92
United Kingdom
My heater a master temp bc 125 seems to switch off before reaching temperature.
So if I set it to 84 say it tends to switch off at 82. It doesn’t always do it, sometimes it will heat to temp set. Pump timer Is off so not being caused by pump switching off.

Any suggestions?
 

HermanTX

Gold Supporter
May 20, 2020
785
Katy TX
I have a Master Temp and was told by installer that he set main temp. on the heater panel to 100. Thus I can not exceed that even if I set a higher temp on my remote access. He also told me never to touch the heater panel to turn on heater that I should do everything via remote. Therefore you may want to check what your heater panel is set at. Good Luck
 

UKjames

Silver Supporter
May 1, 2020
92
United Kingdom
I have a Master Temp and was told by installer that he set main temp. on the heater panel to 100. Thus I can not exceed that even if I set a higher temp on my remote access. He also told me never to touch the heater panel to turn on heater that I should do everything via remote. Therefore you may want to check what your heater panel is set at. Good Luck
Thanks - I’ve only got a heater unit. I haven’t got a remote so the only controls I have access to are the little panel on the heater itself.
 

HermanTX

Gold Supporter
May 20, 2020
785
Katy TX
Let me provide some additional comments. I assume the service light (on far left of panel) is off so the heater should be in operating mode. Also, all gas lines are open. The heater will turn on only if the water temperature is lower than the set temperature of the heater. If you press heater on (either set for spa or pool) then press the up or down arrow to set the temperature you desire.

I think the maximum temperature is 104 deg F. When you push the up arrow, will it go to 100 or higher?

There is an auto cut off if the pump stops and normally the pump should run 5 mins or so after the heater is turned off to cool it all down. Hope this helps or if any thing is different from my assumptions, let me know.
 

UKjames

Silver Supporter
May 1, 2020
92
United Kingdom
Yes it seems to work without errors when I first set it.


good shout for the pump. I did make that mistake once before Leaving the timer set and boiled the water in the heater when the pump stopped, so now I put the pump on manual when I’m running the heater.

So if the pool is 77 say, I set the heater temp to 80 and it fires up. Sometimes it makes it to 80 other times it seems to stop at 79. I can’t seem to fathom why.
 

HermanTX

Gold Supporter
May 20, 2020
785
Katy TX
There are different sensors maybe. The heater has 1 sensor that controls its operation. You may have another sensor in the flow loop (external of the heater). Also these sensors always have +/- errors on accuracies so 1 degree wouldn't be that terrible.