I have a 3 yr old Pentair MasterTemp 400 (LP) that won't light. When I start the heater, the blower comes on right away. After about 20 seconds, there's a loud buzzing noise that seems to be coming from the gas valve. It continues for 7 seconds then stops for about a minute and repeats. It does this 3 times before shutting down. The Fenwal Automatic Ignition System flashes the red error LED 3 times (Ignition Lockout). No error messages on the LCD panel and no red LEDs on back of the circuit board. Appreciate any tips on what to check. A new gas valve runs about $320, so I'm hoping it's something else.
Pentair MasterTemp 400 Heater Won't Light
- Thread starter rrinsa
- Start date
-
- Tags
- heater problem
- Jul 21, 2013
- 52,449
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Welcome to TFP.
Do you get a puff of heat out of the exhaust before it shutdowns? If not then check the igniter . Read Pentair MasterTemp Heaters - Further Reading
If yes then read Heater Flame Sensing - Further Reading
www.troublefreepool.com
Do you get a puff of heat out of the exhaust before it shutdowns? If not then check the igniter . Read Pentair MasterTemp Heaters - Further Reading
If yes then read Heater Flame Sensing - Further Reading
Pentair MasterTemp Heaters - Further Reading
www.troublefreepool.com
swamprat69
Well-known member
A buzzing noise is usually a symptom of a relay not fully closing or possibly a gas valve solenoid that is not fully opening. This can be caused by a physical problem such as a manufacturing defect or wear and tear. It can also be from insufficient voltage to the relay or gas valve solenoid to operate it correctly. You should put your fingers lightly on the gas valve as the heater is attempting to fire up to see if you can isolate the buzzing/chattering to the gas valve. If it is the gas valve and you have a multimeter, you should check the voltage and amp draw of the gas valve as it is being powered. Excessive amp draw above the gas valve nameplate amp draw would be indicative of a gas valve solenoid that is not fully opening. There are a couple less frequent causes, but not knowing your heater set up it is usually best to check the more obvious causes first.
While its buzzing, give it a sharp rap with a hammer. Wonder why Swamp didnt advise this first. Insider trick.
Time to change it out. Let Pentair know, if its a package with two other Pentair products, its covered under a three year warranty. Check the orifice for debris. Have the gas company put a manometer on the valve to see if the gas press. is in specs.
Time to change it out. Let Pentair know, if its a package with two other Pentair products, its covered under a three year warranty. Check the orifice for debris. Have the gas company put a manometer on the valve to see if the gas press. is in specs.
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Just to follow up, the hammer part was levity. Typically when a coil operated valve starts buzzing, you change it out.
my Mastertemp 400 is about 10 years old but may still be relevant to yours. I just installed a Intellicenter controller. My Mastertemp 400 doesn't have the RS485 port so I connected the Fireman switch to the 2-wire gas heater plug on the intellicenter. Inside the electrical box on p34, I found a loose white wire, wasn't sure where it went, I was very careful in there, so I marked it and set it aside. When the time came to test my heater, the fan would fire up and it sounded like it was about to start and it'd do this twice, then I'd get a tiny hint of a smell of gas. I looked in there and noticed where the loose white wire was supposed to go. I made sure the rest were fully seated while in there. The right red arrow points to the connection that came loose in mine.
HTH....
HTH....
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Just want to update this for anyone experiencing the same problem. The symtoms pointed to a bad gas valve and that’s what it turned out to be. Replaced it and now the heater is back in service. Decided not to tackle it myself because 1) I didn’t want to buy a $320 part that I wasn’t sure was faulty, and 2) I’ll leave working on gas lines to the pros.
Hi....I've got a similar issue with my Mastertemp 400. My valve buzzes just as you described, but successfully ignites on the first attempt as long as the outside temp is about 70 or higher. But usually I'll have problems with striking ignition at anything less than 70 degrees outside. So I think the cooler temps are making it difficult for the solenoid to drive the valve open. Was going to replace the ignition control module, but after reading this thread, think the better move would be to replace the gas valve. But just wondering about how much the plumber charged you to replace the valve?