(no) fire in the hole

[cheeseheadincarmel]

Hi,

I have a Raypak 2100 pool heater (C-R206A) with the digital ignitor. Over the weekend, I got the RLS (rollout switch) error. I bypassed that switch to see what the flames looked like, and sure enough, they rolled out the front, right by the rollout switch. The flames inside the burner chamber were yellow, not blue. I have another Raypak 2100 on my hot tub (about 100' farther from the house), so I was able to see/hear the correct ignition sequence and what the flames should look like.

I dismantled the upper half of the heater and power washed the soot from the heat exchanger. There was a good bit of soot in there - significant airflow restriction, I'm sure. I replaced the bypass valve (definitely shot), and the unitherm governor (maybe ok - opened a little in hot water - but I replaced it anyway). I put everything back together this afternoon. I had no leaks (yay), but also no fire (boo).

When I try to fire it up, I hear the gas valve click open, and it tries to spark (SPK on display, and I hear the zapping sound). However, the pilot never lights up. I let it try to spark for about 30 min, to no avail. I do not smell gas anywhere around the heater. It seems that I'm not getting gas to the pilot (blocked pilot orifice?). However, when I did have fire last weekend, those flames didn't look right compared to the heater on my hot tub. Does that mean the gas wasn't getting to the burner tray, either? Or is the sooty heat exchanger enough to make the flames yellow instead of blue?

With the hot tub doing fine another 100' farther away, I don't suspect gas pressure (both have 3/4" iron pipe for the gas lines). Check that pilot orifice first? What else should I look for or try?

I appreciate any thoughts or suggestions.

 

[Casey]

Welcome to TFP!

Heaters are not my specialty but someone will be along to help you!

Enjoy the site and read Pool School, there is a wealth of educational links that are too good to pass up! We also offer the best test kits around!

 

[danpik]

Did you pull the burner tray and pilot assembly when you washed it? I am thinking maybe you got something blocking the pilot orifice. It is real small so it does not take much to block it. you did turn the gas valve on, correct?

 

[cheeseheadincarmel]

I removed the heat exchanger when I power washed it, but I haven't taken out any of the burner/ignitor parts yet. Yes, gas valve is on.

Do you have to disconnect the gas line to the heater to remove the burner tray and pilot assembly?

 

[ps0303]

Yes you have to disconnect the gas line where it comes into the gas valve. Then you can remove the retaining screws that hold the burner tray in place.

FYI, you don't have to remove the heat exchanger to clean it. Also, power washing inside can destroy a few things like the refractory on the sides.

 

[cheeseheadincarmel]

Thanks, Paul. Sorry for any miscommunication - I did not power wash the inside of the heater. I took out the heat exchanger so I could power wash the heat exchanger - it was pretty gummed up with soot. Would the restricted airflow from the sooty heat exchanger be enough to make the flames appear yellow instead of blue, or do I need to think about problems with the gas delivery in general (pressure, blockages, etc)?

 

[ps0303]

Sooted up exchanger can cause it to burn bad as well as pushing the flames out toward the front of the unit.

 

[cheeseheadincarmel]

To tie a bow around the story, I removed the pilot assembly and cleaned the orifice on the gas line to the pilot (blew compressed air through the tube that feeds the pilot). When I put it back together and tried to start up the heater, I still had no pilot flame, but I could smell gas. I replaced the pilot assembly, figuring that the ignitor had gone bad, and that solved the problem. The part was $50 online. One other note - it is possible to take out the pilot assembly without removing the burner tray - there is a screw in the lower right corner as you look at the front of the heater that holds the bracket for the pilot assembly. At the main gas valve, just disconnect the little gas tube that runs to the pilot, then once you remove that screw, the whole bracket can slide out. That's handy, since you don't have to mess with the main gas line that comes into the heater.

Thanks much to Paul and danpik for the advice!