Hi all!
I know I'm not the first one to have a broken down Mastertemp 400 with an SFS error LED on, but the earlier post didn't solve my particular problem. My propane heater has been working very well for the past few years. Installed in 2013, my first few years had mouse problems but I finally covered all openings with wire mesh and have not seen mice since! Full disclosure; mice lived in the main control box for a few awhile one winter and chewed the heck out of many wires. I got a new wire harness but in the end I simply fixed just the bad wires with fresh splices and have had no problems for the past 4 or 5 years. It baffles me why they can't make the housing mouse proof- but that's another issue. Flash forward to the other day when I found the heater turned of with the service light on. Cranked up the filter pump to top speed and reset the heater- it went for awhile, the exhaust seemed hot, but the water coming out was lukewarm and eventually it stopped and the service light came on. Checked the error LEDs on the control board and the SFS LED was on and temp LCD just said the temp- no error codes. I had a replacement Stack Flue Sensor so I put it in and restarted- heater still stopped. Tested the old stack flue sensor continuity (which looked dirty/sooty on one side) and got a 4.0 reading, which I think is fine, so probably not the problem. Tested the exhaust temp with an instant meat thermometer and got around 350 F, which seems in range. So, far all you heater experts what is my next step??? Going through Pentair troubleshooting steps it says: Check pressure and volume of fuel supply- but how? and all valves are open- would that somehow decrease? It says: Check continuity in wiring harness between Control Board and Probe. Continuity OK? How do I check that? Disconnect the connector from the board and test the connector ends with the meter? Not sure what to do next so hoping someone could help. Maybe I should just replace the whole wire harness with the new one I still have or just go ahead and replace the control board. I don't know. Thanks for your time!
I know I'm not the first one to have a broken down Mastertemp 400 with an SFS error LED on, but the earlier post didn't solve my particular problem. My propane heater has been working very well for the past few years. Installed in 2013, my first few years had mouse problems but I finally covered all openings with wire mesh and have not seen mice since! Full disclosure; mice lived in the main control box for a few awhile one winter and chewed the heck out of many wires. I got a new wire harness but in the end I simply fixed just the bad wires with fresh splices and have had no problems for the past 4 or 5 years. It baffles me why they can't make the housing mouse proof- but that's another issue. Flash forward to the other day when I found the heater turned of with the service light on. Cranked up the filter pump to top speed and reset the heater- it went for awhile, the exhaust seemed hot, but the water coming out was lukewarm and eventually it stopped and the service light came on. Checked the error LEDs on the control board and the SFS LED was on and temp LCD just said the temp- no error codes. I had a replacement Stack Flue Sensor so I put it in and restarted- heater still stopped. Tested the old stack flue sensor continuity (which looked dirty/sooty on one side) and got a 4.0 reading, which I think is fine, so probably not the problem. Tested the exhaust temp with an instant meat thermometer and got around 350 F, which seems in range. So, far all you heater experts what is my next step??? Going through Pentair troubleshooting steps it says: Check pressure and volume of fuel supply- but how? and all valves are open- would that somehow decrease? It says: Check continuity in wiring harness between Control Board and Probe. Continuity OK? How do I check that? Disconnect the connector from the board and test the connector ends with the meter? Not sure what to do next so hoping someone could help. Maybe I should just replace the whole wire harness with the new one I still have or just go ahead and replace the control board. I don't know. Thanks for your time!
