Pool heater not cycling on/off

esajl

0
Jul 18, 2012
6
I have a Raypac 2100 (nondigital) pool heater. When my pool was opened, the heater didn't work: the pilot stays on, but the heater doesn't ignite, at all. I would think it's the thermostat or igniter, but the pool company that has come out (which I'm beginning not to entirely trust) says that it needs a new gas valve (which doesn't make any sense to me, since the pilot is operational), or, preferably a new heater. Since I plan to put my house on the market next spring, I would obviously prefer not to spring for a new heater. I called Raypac and they said they don't speak with end users. Any suggestions?
 
Most likely it is not the gas valve. I am pretty sure this is a milivolt system which uses a powerpile to generate a milivolt current to power the gas valve. There are a couple of ways to check this system to ensure it is working properly. The first is with a milivolt multimeter/digital volt meter. Item #3 in the attached picture is the gas valve. Using the meter, check for the voltage reading across terminals "d" and "e". The reading should be 750 milivolts. If it is, then the powerpile is good. If it is 600-650 it is marginal and anything lower than that the powerpile needs to be replaced. If you are getting 750 milivolts at terminals "d" and "e" then a jumper wire across terminals "d" and "f" should open the gas valve and light the burners. Jumping across these two terminals will bypass all safety switches and thermostats in the system. (on your valve, Terminal "d" will/should be labeled th/tp, "e" should be labeled tp and "f" should be labeled th. ) If the burners light this way then the problem lies in the safety switches in the system. Again these are not too hard to test. Simply follow the wires from the th/tp valve to each switch. Unhoo the wires from the switch and put the jumper wire between the two wires to make the circuit. if the burners light then you found the bad switch.

If you have good power from the powerpile and jumping across the terminals on the valve does not light the burners then the gas valve is indeed bad

gashtrmillivolt2.gif
 
esajl said:
Sounds complicated, but I will get on it.

No, not very complicated. It is realy a simple system. If you look at the diagram I provided it shows the path the voltage takes to open the valve. Each of the sensors along the path act as on/off switches. Jumping the gas valve at the th/tp,th terminals simply bypass all of them. and is simply puting direct power to the valve.

esajl said:
You seem to assume that it is not the thermostat or igniter, is that correct?


If you have a lit pilot light then there is no igniter. It is possible that it could be the thermostat. I doubt it though. I would be more inclined to think a bad pressure switch. If you follow the arrows on the drawing I provided it will show that most of the switches and thermostats are inline. Think of the old "if one goes out they all go out christmas lights". This is the same concept. If one switch does not make contact then the rest will not do anything. This is why we need to test the powerpile and the gas valve by jumping the terminals and testing the output of the powerpile.

If I had to make an educated guess on this I would put the powerpile at the top of the list for failed parts.
 
esajl said:
but the pool company says that it needs a new gas valve (which doesn't make any sense to me, since the pilot is operational).

Not saying you need a gas valve, but you can have a malfunctioning gas valve that would allow the pilot to stand and no main. Gas valves are actually two valves. One for the pilot, and the other is the main.
 
I purchased a multimeter and the reading I got was 315-320 mv, which, according to the above posts means that I need a new "powerpile." Problem is that I've gone online for Raypac 2100 parts and do not see anything labeled "powerpile." Is there another name for this?
 
esajl said:
I purchased a multimeter and the reading I got was 315-320 mv, which, according to the above posts means that I need a new "powerpile." Problem is that I've gone online for Raypac 2100 parts and do not see anything labeled "powerpile." Is there another name for this?

Sounds like you found the problem. As long as the end of it is fully enveloped in the flame and you are only seeing that output It does need to be replaced. Check your yellow pages for a plumbing supply house and purchase one from them. These are universal parts and they will have better prices on them than Raypac will have. I just did a quick search and did not find that part serviced separatly. It was bundled together with th pilot assembly on some sites. I replaced one last week and it was about $25.00 from my local supply house.
 
I have a fairly similar issue and I'm wondering if it would be the same cause. When we purchased our house we were told this unit worked. We used it twice and noticed it turned off/on constantly. However it would stay on longer periods as it ran longer. basically at first cycling on/off every minute or two and gradually it stayed on for 4-5 minutes, then 10+ minutes until it just remained on. Also of note was that I had to hold down on the pilot for longer than the instructed 30 seconds (more like 2 minutes) to get it actually started the first couple times. When pressing the pilot knob down, there is a much larger flame and I assume this is where/when it generated the millivolts.

After the first two uses, it completly stopped working, or at least turning on. The pilot lights perfectly fine, and remains on. However no matter how long I hold the pilot switch down (instructions say 30 seconds), the main burners never ignite for more than 30 seconds and then shut down.

So, is the powerpile utilized after the initial lighting of the burners? Or am I looking at something else.

My hurdle now is when I installed the new pump, I disconnected the heater all together as I felt it was not working, so why bother. To test anything I guess I'll have to re-plumb the heater.
 

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The power pile servs two functions. First is to verify to the gas valve that the pilot light is lit. The second is to provide electrical current for the gas valve's main burner circuit. This voltage should be 750 MV idealy. The burners once lit have a proving circuit all their own in the form of a flame sensor. There are optical sensors on some high end equipment but, most have a wire probe that has to be in the flame in order to work properly. By the symptoms you described I would suspect that the flame sensor is dirty or the burners may be clogged up a bit and not allowing the probe to see the flame.
 
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