Raypak R406A wont fire

[mgill]

Edited post to note my sig description of my equipment is not up to date - it refers to my old heater. This post is about my new heater but forgot to update sig!

Hello everyone, Im looking for some feedback on my situation. (some pics attached)

We had a local pool company install a Raypak R406A (MN: P-R406A-EN-C, SN: 1512290169) in 2016, so its not yet six years old. We use the heater frequently for about half the year in the summer and during the winter it typically gets used every other month for the hot tub. We live in Northern California so the heater never sees snow and rarely sees rain. Its a mild climate. The heater is not remote controlled - we use the front panel when we need it. (the front panel started becoming non readable in year four - but that didnt affect the function of the heater once it was set so I never addressed that issue - thoughts on how to replace the screen would be appreciated too!)

I went to use the heater last week and it clicks, but does not fire. I pulled the front of the heater off and took a look inside - the two wires that run from the panel down the left side and to a device that I think looks like the Flame Roll-Out Safety Switch are completely melted through - meaning they are raw wires (pics below). They may still be working for all I know, Im not sure if that would produce the behavior Im seeing. Everything else I can see is dirty from being outside, some spiderwebs but no obvious issue.

The pool company came out and just sent me an email - here is a quote: "we have looked at the inside of the heater and determined that the burners, igniter and temperature sensor most likely need to be replaced". Given the behavior I might buy the igniter issue but I have a hard time believing the temp sensor or the set of burners is my problem given im not even 6 years in. But Im certainly not the expert.

Id appreciate some opinions on what to do - where can I start? Im fairly handy but know nothing about the inside of a pool heater.

Thanks all.

 

[ajw22]

You can start by showing up pics of the burner area.

@swamprat69 can help you evaluate the heater.

 

[swamprat69]

Any gas heater needs to be cleaned and inspected on a regular basis. The height to which the rollout switch wire insulation has been burnt/melted off on the left hand side and the discoloration/sooting ( hard to tell which from the photo) of the cabinet in that area are indicative of severe flame/heat rollout. This can be due to any of several causes ( gas path obstruction, gas/air mixture obstruction, heat exchanger obstruction [sooting etc.] or flue gas obstruction et.al.). What is needed is a through cleaning and inspection by a qualified technician to include gas manifold orifices, burners, heat exchanger (for sooting/obstruction) and flue gas path. As to replacement parts needed... burners and ignitor possible depending upon inspection results (after being pulled and inspected) and if they are referring to the rollout switch as the "temperature sensor", I would recommend replacing that. You would also need to replace the rollout switch wiring with wiring that matches the original wiring specifications as that is how the heater was approved/certified. Not sure about the competency of the pool service as they seem to be recommending burner replacement and it doesn't look like the burners were pulled and inspected?? Might not be a DIY if you are not familiar/capable and safe working with gas and electrical as you would need to take apart the gas piping and wiring from the gas valve in order to disassemble and inspect the needed components. More than happy to answer any other questions that you may have.

 

[mgill]

Thank you. Im fine with electrical, but low experience on plumbing/gas. I just tore down the entire unit and cleaned it out (I did not take the core apart) - lots of leaves, small debris and other items. brushed everything out and then vacuumed. Ive also (with the help of TFP!) found my path to fixing the screen with a replacement part and I ordered a Raypak wiring harness today - will just replace the entire harness. Ill add the temp sensor to the list.

Regarding the burners Im not ready to pull the gas line so here are some photos I could get in place - mostly from the side and the bottom. I sure dont see much to be worried about but you may tell me I have to do a full pull to be sure. Would appreciate your take on these additional photos.

Regarding the pool company - its a local business and I was trying hard to support them. But this feels like a stock answer without alot of inspection or analysis. They always wanted to do 'solar inspection' on my heat exchange panels on the roof for an extra charge but they never asked to do a full inspection on the heater. I would have supported that. I may be on my way here to finding new help.

Thanks again for helping! Photos of the burners below:

 

[swamprat69]

By "core", I assume that you mean the finned heat exchanger. When you mention that you "tore down the entire unit", did you mean disassembling to the point that you could directly observe/clean the top of the finned heat exchanger? Without further disassembly you might be able to get a fair idea of the state of the problem using a flashlight and an extendable inspection mirror to check for heat exchanger fin blockages from underneath looking for dirt/soot blocking the flow of combustion byproducts through the heat exchanger. You could also check the burners for any blockages full/partial of the burner slots at the top of the burners. Depending on the amount of room available, you might be able to ream out the gas manifold orifices with a bent pipe cleaner in an attempt to clear any spiderwebs. If you can get the heater to fire, observation of the burner flames would tell you a lot. Burner flames should be solid blue in various different shades. Any yellow in the flames would be indicative of oxygen starvation in the combustion process. It is normal to see some orange sparkling in the flames in a heater that has not been run in a while ( this is just dust that has been entrained in the gas/air mixture and should stop in a short while ). If the heater fires and runs, you could check for any flue gas spillage by running your hand/fingers along the bottom/sides of the panel labeled "For your safety..." . There should be no excessive heat in these areas as all airflow should be into the burner compartment and gasketing should prevent any leakage from other spots.

 

[mgill]

Thank you - yes, thats what I meant by 'core'. I cleaned and vacuumed the fins so they have no obstructions.

So my next steps - I have ordered a new wiring harness and temp sensor. I will re-open the heater and replace those two items, and try to get it to fire back up - and will attempt to see through to the burners. I completely understand your descriptions. Thanks so much for the feeback.

Im out of town this weekend, so will be a week or so before my next update. But will report back what I see.

 

[wireform]

I don't know that exact heater but I believe the burner tray would be removable just like other brands or atleast the burner tube should be removable with minimal fuss.

 

[mgill]

Update - just got done with some part replacements:

• New LCD display, I can now see what the heater is telling me
• New wiring harness, I did not replace all wires. I replaced the harness that melted down - all other wiring looks safe and intact
• New temp sensor along with the new wires with the wiring harness

After putting everything back together the heater turns on but the behavior has not changed. When I press the Mode button and call for heat I can hear it sparking but it does not light up. The parts I replaced had to be replaced anyway so Im not too discouraged yet!

I think I now need to figure out the ignition and the burner tray. Any additional insight or recommendations would be appreciated. Thanks.

 

[donfrank]

I had an issue with my 15 year old heater last year. It was kicking off the breaker. You mentioned cleaning out debris could thos wires have been chewed up by small rodents? That was my problem. Rewired the damaged area and put some camphor packets as a deterrent and it everything worked fine. Will check again on open this year. Good luck !

 

[swamprat69]

If you are getting sparking, there are several questions that need to be answered. Are you getting a strong spark from the pilot electrode to the pilot flame hood? Are you getting correct gas pressure to the pilot flame ( both correct pilot gas pressure and no restriction from a dirty pilot orifice)? The spark should occur between the tip of the electrode and the closest point on the edge of the pilot flame hood. A dirty electrode or pilot hood will cause a weak spark that may "wander" rather than hitting the pilot hood in the same place every time and may not ignite the pilot flame. Are all of your grounding points also clean bare metal?

 

[Poolbreh]

You can also check the ags pv/c/mv for 24vac just to confirm there is enough to open that pilot valve. That and what’s listed above will narrow it down. If everything checks out you’ll have to check gas wc.

 

[ajw22]

I would check the gas and gas pressure first using a manometer. It is a waste of time to run after other problems without knowing you have good gas at the gas valve.

 

[Poolbreh]

I agree manometer would rule out a lot.

 

[mgill]

Hi everyone! Thanks to everyone for their help and feedback.

The heater has fired and is currently on. Here is the path I followed:

• When I opened the heater it was obvious that heat was coming out the front of the heater rather than the top - and some wires were melted to bare wire and touching each other. I ordered a new wiring harness and replaced the damaged wires, and also replaced the temp sensor at the end of the melted line.
• Replaced the LCD panel as the old one would distort when warm - not directly related to the firing problem but a step nonetheless.
• Replacing the wires and the temp sensor did not change the behavior - the sound of sparking but no fire.
• Next step was to pull the ignitor - I replaced the ignitor and the bracket, as the old bracket was severely rusted out.
• During installation of the ignitor I made sure the pilot gas line was clear of obstructions, and I re used the old line to the new ignitor.
• Turned gas and elec back on and it took two rounds of sparking and the unit fired up!
• Next step was to dig in to the valve and get a manometer as some of you suggested - glad this is as far as I had to go.

Pics below are the new wires and the burners fired up. Thanks to everyone for their help, I really appreciate this community!

Mark

 

[swamprat69]

The photo of your burners while the heater is firing appear to show a significant amount of yellow tipping on the flames. This is an indication of incomplete combustion and means that you still have a problem due to the various reasons stated before. I would hate to see the work you have already done wasted. You really need to get the heater cleaned and inspected by a competent technician in order to avoid repeating any of these problems and operating the heater safely.

 

[mgill]

The photo of your burners while the heater is firing appear to show a significant amount of yellow tipping on the flames. This is an indication of incomplete combustion and means that you still have a problem due to the various reasons stated before. I would hate to see the work you have already done wasted. You really need to get the heater cleaned and inspected by a competent technician in order to avoid repeating any of these problems and operating the heater safely.

Got it, thank you. Thats the reason why I posted the follow up photos! Im working to find another pool guy, will ask him to do a heater inspection.