Raypak(Rheem) Heater Not Igniting. Bad Gas Valve?

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303Michael

303Michael

Active member
Jul 8, 2019
30
Denver, CO
I'm hoping to get some direction from someone smarter than me. I've had the pool and heater up and running for a couple of weeks and the heater seemed fine until a couple of days ago. I can hear and see the electric ignitor sparking repeatedly but it's like there's no gas there to ignite. The fault code is "no pilot sensed"

The heater is an P-M366A-EN-C with a Hoenywell VR8304k4814 valve.

I have a multimeter but I'm not sure what leads to check to make sure the valve is getting power. Or maybe it's something else entirely so any feedback would be appreciated.

Thanks.
 
Is the gas cock open? Is the main gas valve in the heater in the "on" position? Yes?
Does the pilot actually light? Use a small mirror to look. If so, it is not sensing flame. Clean the pilot burner as it also is the flame sensor.
If not put your meter in DC voltage range. Place one probe on PV terminal and the other to a bare metal. Try to light heater and while the igniter is sparking you should see 24v.
Just places to start.
 
1poolman1 said:
Is the gas cock open? Is the main gas valve in the heater in the "on" position? Yes?
Does the pilot actually light? Use a small mirror to look. If so, it is not sensing flame. Clean the pilot burner as it also is the flame sensor.
If not put your meter in DC voltage range. Place one probe on PV terminal and the other to a bare metal. Try to light heater and while the igniter is sparking you should see 24v.
Just places to start.
Click to expand...
Thanks for the reply and sorry for not including more background. Yes, both the outside valve and the valve in the heater are open. The heater was functioning without issue for a couple of weeks leading up to this failure.

As far as I can tell the pilot is not actually lighting. I'll get a mirror in there to confirm but I'm fairly certain it's not. I've been reading through other threads and was going to pull the pilot burner out to clean it while I was in there but I can't figure out how it comes out.

I put my probe on the PV terminal (top one with red/black wire coming in) and it read 0.75v. So either I'm reading it wrong or there's an issue there?
 
To clean the pilot you will, likely, have to remove the entire burner tray. Not real difficult but will require removing the gas line from the main valve. Don't lose the screws. Take a picture of the wiring as it will have to be removed as well. There should be 24v at the PV terminal when the pilot is trying to light. If not, the gas valve won't open that circuit.
 

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1poolman1 said:
To clean the pilot you will, likely, have to remove the entire burner tray. Not real difficult but will require removing the gas line from the main valve. Don't lose the screws. Take a picture of the wiring as it will have to be removed as well. There should be 24v at the PV terminal when the pilot is trying to light. If not, the gas valve won't open that circuit.
Click to expand...
Thanks for the additional info. I'll go through that follow chart. Am I correct that the board is behind control panel and to access it you remove the control panel?
 
Set your multimeter to vac check between pv(pilot valve) and mv/pv(common) on gas valve for 24vac. The pilot should open first after a 7-10 seconds the mv(main valve) for the burner opens. You can test the main valve the same way after 7-10 seconds you should get 24vac across mv mv/pv. If you have propane check your tank and any valves leading up to it. You can undue the tubing and single screw and it should come out. You should visibly be able to see a spark across igniter.
 
Poolbreh said:
Set your multimeter to vac check between pv(pilot valve) and mv/pv(common) on gas valve for 24vac. The pilot should open first after a 7-10 seconds the mv(main valve) for the burner opens. You can test the main valve the same way after 7-10 seconds you should get 24vac across mv mv/pv. If you have propane check your tank and any valves leading up to it. You can undue the tubing and single screw and it should come out. You should visibly be able to see a spark across igniter.
Click to expand...
Thanks. I just went and did this with the meter on vac and got 29v across pv/mv-pv. I can see the igniter sparking so I seems like I'm not getting gas. I'm guessing either the pilot is clogged or the valve has failed. Anything else worth looking into?
 
There should be a faint click when voltage is applied. That is the pilot valve opening. If you use natural gas, disconnect the pilot tube at the valve. If gas flows the pilot burner is clogged (If you are a smoker, don't). You should smell it almost immediately. If not the valve is bad. DO NOT DO THIS IF YOU USE LPG.
 

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I pulled the pilot tube off the valve and I could hear and smell the natural gas coming out when the valve opened. When I finally figured out how to get the pilot assembly out, I couldn't blow air through the pilot tube, so it got clogged up somehow. Everything around the pilot was pretty rusted up but I was able to get it opened up and when I reinstalled it the heater fired back up. I'm thinking it might make sense to pick up a new pilot assembly, bracket, and tube to have on hand. I'm not sure the original will survive another go around. Thank you @1poolman1 and @Poolbreh for the assistance.
 
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