I recently purchased two Pentair Mastertemp 125K natural gas heaters off Marketplace. Both sellers said they did not work and had been setting for a few years. I'll call them heater" A" &" B". Heater "A" I took all apart, cleaned and tested all wires and connectors. Replaced some corroded wire ends, reassembled and it works fine. Did the same to heater "B", but it had an E01 error. Wires and thermistor tested OK. Found bad solder connection on the circuit board where the thermistor wire plugs in and soldered it. Now heater "B" powers up Ok, but does not ignite. I swapped both circuit boards, gas valve vale and ignitor with heater "A". The parts from "B" all worked fine in heater "A", but heater "B" still does not ignite using the parts from heater "A"
Checked the following. The blower starts and runs fine, I have 120 volts at the ignitor when calling for ignition, 120 volts at the gas valve when valve should open. Manifold pressure on both heaters measured at -.204 on "A" and -2.07 inches of water on "B". For testing purposes, I replaced the thermistor with a 10K resistor and jumpered across the wires going to the high limit and AGS sensors. The flue stack sensor measured at 4meg ohms. The blower runs fine and I can smell gas during the ignition sequence. I pulled the cover off the combustion chamber and it was clean. I verified the orifice is the same in both heaters. I removed the ignitor and placed it on a wood block and during the ignition cycle it glows white hot and even started the wood on fire. Using the same gas line for testing the heaters and both static and dynamic pressure tested Ok. There are no error codes or error lights, except for the service heater LED that lights after the ignition cycle times out after three attempts. I am at a total loss on what to check next. Does anyone have any suggestions? Thanks.
Checked the following. The blower starts and runs fine, I have 120 volts at the ignitor when calling for ignition, 120 volts at the gas valve when valve should open. Manifold pressure on both heaters measured at -.204 on "A" and -2.07 inches of water on "B". For testing purposes, I replaced the thermistor with a 10K resistor and jumpered across the wires going to the high limit and AGS sensors. The flue stack sensor measured at 4meg ohms. The blower runs fine and I can smell gas during the ignition sequence. I pulled the cover off the combustion chamber and it was clean. I verified the orifice is the same in both heaters. I removed the ignitor and placed it on a wood block and during the ignition cycle it glows white hot and even started the wood on fire. Using the same gas line for testing the heaters and both static and dynamic pressure tested Ok. There are no error codes or error lights, except for the service heater LED that lights after the ignition cycle times out after three attempts. I am at a total loss on what to check next. Does anyone have any suggestions? Thanks.
