I have an old Raypak pool heater, just turned 16 years old. This is very old for a pool heater, so I was ready to buy a new one when I tried to turn it on, and it didn't work. But I decided to see if I could fix it, and here's what I did to troubleshoot and fix. Depending on what's wrong, this may or may not help you.
My problem was I was not getting a spark to start the pilot. When the heater is working you hear a clicking noise when it fires up. This is the spark which starts the pilot, which in turn lights the heating element.
I have a RP2100 heater, low nox version for Calif., actual model number is something like P-R335A. The display failed one under warranty, and was going a 2nd time, so I setup it up for remote control so I could stop using the display. The display is something like $300, so its not worth it to keep replacing, and seems to be a weak link in this heater. Other than the display, its worked great until a couple weeks ago, when it would not fire up.
To troubleshoot, you need a volt meter to check to see if you have voltage where you need it. I also used a soldering iron, and a couple of screwdrivers.
There are four screws that are on the sides of the front panel which contains the display. This is the rectangular piece that is almost as wide as the heater, on the top of the front side of the heater.
I turned off 220V to the heater. Make sures its off, my 220V also goes to my pump, so its easy to tell if 220V is off. If not sure, turn off your main so all power is off. Then you remove the screws and then you push up the front a bit, and it will pivot down.
When its down, you can see there is big piece of plastic covering a board that connects to the display, in the part that pivoted down.
On the front of the heater, there is a module and a bunch of wires.
On the module, it has a couple pins that say 24V. I turned 220V back on, and turned my pump on, then measured power here at it read about 7 V. Set the meter to AC Voltage. So that's not good. I thought the transformer that converts 220V to 24V may be back, or a bad connection, but it turned out I needed to measure somewhere else.
220V comes into the side of the heater, and then it goes to a transformer that is under a cover on the far right side of the heater. Unscrew two screws, and the cover will come off. You need to carefully more the cover out of the way, there are a bunch of wires so it is kind of hard to move. The transformer will be loose too, but the wires hold it in place. 220V goes straight to the transformer, and then a blue and yellow wire come out of transformer, this is the source of 24VAC, which provides the power for the heater. 220V is used for the fan motor and this transformer, but nothing else I could see.
Heres a picture, the white in the square hole is part of the transformer. You can see the blue and yellow wires coming out of the hole. The green wire is ground.
24VAC on the blue wire goes to a switch on the side of the heater, the on/off switch for the heater. I never knew the heater had this switch, because its on the side of the heater against a wall so I never saw it lol.
Then the blue and yellow wires go into the top part of the heater, to the controller board.
Turn power off, you can use the switch on the side of the heater to turn off power if you like, its easier than turning off the 220V breaker.
If you remove two screws that hold down the black plastic cover, you will see the board.
On the left side of the picture above, you see the connector that brings 24VAC and ground to the controller board. If you stick your meter probes in the connector, you should see about 24VAC. My voltage was around 26VAC, it depends on what your 220V is, and mine is a little higher.
So 24VAC was going into the controller board, but I figured out it was not going out. It goes from the controller board to the module I showed in the first picture. The connector in the middle of the three side by side connectors goes to the module. The module is a Honeywell S8600H, and this module generates the spark for the pilot, so if it doesn't get power, no spark and no fire.
I traced power through the controller board. To do this, I had to scrap off the conformal coat that protects the board. Used an exacto to scrap some off, the a soldering iron the re-tin the pins and kind of melt the coating, so I could get a probe to the pins.
This pictures is from the back of the board. I unscrewed four screws that hold the board in place, then removed all the connectors to get it out. You may not need to do this, but its not that hard. The one big connector, I used a flat head screwdrive to help pry it off, but be careful not to damage any parts are traces if you do this.
So power comes into the board in top left of pic. Left pin is H (high but there really is not a high for AC, but this is from the blue wire that goes through the on /off switch).
L goes directly from the power input connector the the connector for the Honeywell module. H goes to the first pin of the big connector. All of the safety lockouts are wired to the big connector, and alternating pins are shorted together. The black marks are in between pins that are shorted together.
So power goes into the left of the connector, and then goes through a bunch of safety sensors for things like water flow, and then comes out on the right side.
Then H goes to a relay. The long black lines show how H is routed. H should go through the relay, and then to the Honeywell connector. But in my case, H was not getting through the relay. I don't know if the signal was missing to turn on the relay, of the relay failed because of age and the elements. So I soldered the wire you see across the relay, and now H makes it all the way through to the Honeywell connector.
After I added that wire, I connected everything back up, and now I see 26VAC at the honeywell connector. And when I turned on the heater with my remote control, it fired up.
I had one other problem, I had changed my remote control to a diy setup this summer, using relays to control my pump and the heater. So some reason, when the heater relay turned on, it turned off the pump relays, and the pump would stop, so the heater would stop too.
I decided to just short the heater control wires together.
It works now, I just have to use the on/off switch on the side to turn of and off the heater.
Since I only use the heater when the water is cold at the start of the season, this will work for me.
BTW, to control the heater, the orange/black wires go to one side of a relay, and the yellow black to the other side. Close the relay to short the wires, and the heater turns on, as long as the heater is set for remote control.
Otherwise, I could probably put the heater control on a different relay, that is not connected to pump relays, although it should not matter. I could also add a relay to control heater power, but I expect just using the switch will be fine. I rarely use my the heater, but when I need it, its now working.
