Pentair Mastertemp, NEW: blower wont start

Fleury75

New member
May 24, 2018
4
Chilliwack
MasterTemp 125 Natural Gas (w/cord)
https://www.poolsuppliescanada.ca/p...low-nox-natural-gas-swimming-pool-heater.html
Error Code: Pentair MASTERTEMP 125 Installation And User Manual (Page 42 of 56) | ManualsLib

Heater Sequence of Op: (1) pressure switch, (2) high limit switch, (3) air flow switch, (4) auto gas shutoff, (5) stack flue sensor

New to pool heaters but fairly knowledgeable pool owner otherwise. Ordered online: natural gas connected by a professional, I did all the plumbing.

Turn on the POOL HEATER or SPA HEATER and as soon as I set a temp above current water temp, it 'clicks' and throws an AFS error (air flow switch) on the control board with 'service heater'.

However, the blower never turns on. My question is, does the blower need to be on for the AFS to close, or does the AFS detect via standing air, and once closed, the blower starts? That seems to be what they manual is saying:

From the manual: "The air flow switch (AFS) senses the pressure drop across the air metering orifice. As soon as there is sufficient air flow, the AFS closes, closing the circuit to the hot surface igniter (HSI), which ignites the fuel mixture. On a call for heat, the blower and HSI are energized. In about 20 seconds, the gas valve opens and ignition occurs. The HSI then switches to a sensing mode and monitors the flame. "

The pentair tech says the blower should still come on.

Is it safe to bypass the AFS switch, and if so should I expect the blower to turn on?

Thanks in advance.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
29,060
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Welcome to TFP.

The blower is the first thing in the start sequence to turn on. The AFS senses the blower is on for the start to continue. Jumping the AFS will NOT turn on the blower.

Is this a new unit you installed?

 

Fleury75

New member
May 24, 2018
4
Chilliwack
Thank you for confirming. This means Ill need to open it up and use the multimeter to see why the blower isn't switching on. Ill update shortly.
 

Fleury75

New member
May 24, 2018
4
Chilliwack
I found the issue - after opening the igniter module to do line checks I noticed the 24VAC was disconnected.
When I tried to reconnect it, it was loose - I re-crimped and put it back on tight and the blower started no problem.

This was out of box - had never opened the IM previously. Thank you for the direction.
 
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