Laars LLD Heater_Gas Valve Question

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Pool Tool

Pool Tool

0
May 15, 2014
761
Western Chicago Area, IL
I have an old Teledyne Laars Lite 2 - 250K btu, propane heater that won't ignite. Unit is older but was used last season fairly reliably. It has not fired or run this season.

Situation is similar to this post: Laars Lite Pool Heater won't keep running - Page 2

Observations:
- HSI will glow indicating safeties have been satisfied
- Valve solenoid(s) "click" and will attempt to open but definitely no flame or presence of propane is evident
- Valve will try to open 3 times before HSI and heater shut down
- Fuel line valves are open to Honeywell valve

Tests:
- Measured 24 - 24.8 VAC at the valve when attempting to open over several attempts (one time @ 25.2 VAC)
- Tapping on valve does not affect outcome
- Cracked/opened fitting upstream of Honeywell valve, confirmed propane with leak detector soap
- note: I don't have a gas tester, so it could be air but heater ran last season with no change to fuel line. Does smell like a static gas line.

My questions:
1. What is the best way to check for blockages, spider webs, etc. from the valve to the burner tips?
2. Can I expect a transformer replacement could help? I think no, since I have 24 volts at the valve.
3. Is there anything short of a faulty valve at this point?

Although I don't want to replace the entire heater, I would probably not spend $150 for a replacement valve. But I am open to any suggestions and very appreciative of help.
 
So you hear the gas valve click but you do not smell gas? What does the gauge on the propane tank read? It might be empty but in some cases there is just a little enough gas left in the tank to spit some out when you open the line. Hopefully you have a union close to the valve or so that you can open all the way and check for gas. You should also have a gas **** shut off before somewhere in the line between the heater and regulator, if you have one. You could also have a bad regulator and it is not allowing the proper amount of gas to flow thus not allowing the heater to fire.
 
Thanks for the response.

Valve definitely clicks, I can feel it, but no smell of propane at all. I have copper tubing up to the regulator, tubing then continues from the reg outlet through a ball valve then directly to the Honeywell valve. I loosened the flare nut at the valve and have propane up to that point (bubbled with leak detect soap). Odor was muted but present, typical of a stagnant line. I worked for a gas company and familiar with mercaptan smells.

Propane tank was just filled (80%). We switched providers late last summer and they installed new reg at the heater at that time. Heater did successfully run after that - I am 90% positive. I think the installers were mindful of the 8" w.c. inlet pressure. The pool line is split at the tank from the line to the house with separate reg.
 
You should have a similar pressure tap on the down stream side of the valve you can remove, and feel/listen/smell for anything when voltage is put to the valve.
Note: You can hear the solenoid click in the valve, but that doesn't mean the valve is actually opening, it just means the solenoid is operating.
 
Unfortunately I didn't have time to look at the heater last night. It was dark by the time the littles went to bed and I didn't want another night fumbling with flash lights.

Hopefully today I can pull the valve without destroying the burner manifold - which has pretty good surface rusting. No deep pitting, but enough to make me nervous while unthreading from the valve. Once isolated, I will visually inspect then try to operate with 24 volts while I can see inside. I will also blow out the manifold and the burner tubes to check for obstructions.

If you see anything wrong in my plans, please let me know otherwise I will report back. Thanks.
 
Very unlikely something in the valve itself. Even if you look inside, you won't see very much as the actually working components are in the middle and not visible.
 
Pool Tool said:
Hopefully today I can pull the valve without destroying the burner manifold -

If you see anything wrong in my plans, please let me know otherwise I will report back. Thanks.
Click to expand...

YES! Why are you taking the valve off the heater? You should be able to test without removing the valve. If you don't have a tap on the down stream side, use the one on the upstream side and attach your manometer. If you get a pressure drop, you will know the valve is opening.
 
Thanks for the replies. My propane provider confirmed correct delivery pressure and left gauge installed while the valve cycled or tried to. HSI warmed and the solenoids clicked but there was no pressure drop or smell. No apparent flow of any kind. So I pulled the valve in case I decided to buy a replacement and you are right - nothing to see there.

I ended up buying a new heater, Raypak P-R406A-EP-C, in lieu of replacing the valve. I acquired the old heater with the house 18 months ago. Since I could not determine the age or service history I didn't want to find more issues.

One question - in the off chance natural gas becomes available in my area, can this LP heater be converted? I assumed any appliance can be modified to burn either but read something online (so it must be true) that the Raypak digital unit can't be converted. Thoughts? Thanks again!
 

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So, I just got confirmation...well sort of. Freight company is pretty sure they can deliver the raypak on this Friday - otherwise Monday.

My current arrangement is ~5' of 1.5" pipe from the filter to the heater then the same distance/dia returning to a CV, chlorinator (vacation use), valve (not a 3-way) then to the returns. I am considering adding a manual bypass around the heater. I have read the pros/cons of the manual bypass considering the heater has one internal to moderate flow. One positive is that if i add the bypass i can remove the old heater yet still run the pump until the new one gets delivered/piped up.

My question is - if elect to install the bypass is there any value in running 2" pipe to and from the heater to match its piping? Suction lines are about 30' (SK) and 20' (MD) and returns are 10' & 20' each. All other piping is 1.5 inch.

Thanks
 
If you have 1.5" coming from the filter to the heater and then from the heater to your chlorinator, why mess with it. Just get a couple of 2" to 1.5" reducers to glue into the heaters unions to reduce it down to the 1.5". I do this all the time when needed. No issues with this size of piping. I see many times the builder will run 2" for most of the plumbing but when they get to the filter they reduce it to 1.5". Mostly because the filters union are 1.5".
 
Follow Up: Raypak delivered and installed. Very happy with the unit, installation instructions, etc. Performance has been so much better than expected compared to the old unit. Kids are enjoying the warm pool to say the least.

@ps0303 & Clown - Thank you for the help and advice.

@stebs - Yes, knob was in the 'on' position. Not that i would admit otherwise now ;) Ha, jk - it was definitely in the on position.
 
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