Heater not heating past 94*, tips on maintainance?

[shellsingleton]

I have Purex Triton Minimax 350 heater which wasn't used much last season. I noticed it was slow to heat last season, the few times we used it. Now it won't get past 94* even after a couple hours run time.
My thoughts are to check and clean the jets to make sure they are burning correctly, and I suspect the heat exchanger may be partially blocked due to calcium buildup. My water is not particularly hard, but I would bet the heat exchanger has neven been cleaned in it's 11 year lifespan.
I've never done either of these things so any tips will be appreciated. I will try to find the manual online, and I will do some more searching here to see what others have done.
I think I'd need to remove the exchanger and dip it into a strongish MA solution to clean the scale from inside it? And you'd want a nice blue flame from the jets, similar to what I look for on my grill?

 

[shellsingleton]

Manual can be found here: http://www.pentairpool.com/pdfs/MiniMax ... rMaxIG.pdf
Wish I could find the pdf I had saved on my last laptop, that link takes forever to load.
Does say I'm looking for a blue flame.
Found that a new heat exchanger is nearly $600. All the more motivated to repair rather than replace.
edit-Adobe Reader X threw me for a loop, but I finally saw how I can save a copy onto the laptop.

 

[shellsingleton]

And just to make sure the simple things are out of the way, the propane tank is verified 65% full, and the burners are lighting off and flowing evenly.
I did see that there is about 1/2" of blue flame at the bottom with 2" or so yellow flame above that. So cleaning the burners is first on my list.
The knob is set to max temp on the unit itself.
Guess I can go to bed now.

 

[JohnT]

I can't help, but I know I've seen this problem discussed before. Search didn't give me anything though.

 

[shellsingleton]

Was kinda hard for me to find good search results too.

 

[JohnT]

Was kinda hard for me to find good search results too.

Be sure to use the Google search at the bottom of the page for best results.

 

[shellsingleton]

Aha! That may help.
Right now the plan is to find a good wire "bottle" type. Rush to clean the inside of the burners and use my other wire brush to clean the outside.
Is it common for the outside of the exchanger to need cleaning?

 

[spishex]

Is there still water spilling over into the pool when the spa is heating?

 

[shellsingleton]

No, valves are synced correctly. Good question tho, that would have done it.

 

[Pool Clown]

Have you verifyed that the heater is running the whole time, or is it running, then shutting down, then starts again and repeats?

 

[shellsingleton]

Will verify that this afternoon but I'm pretty sure that it runs constantly when told to.

 

[Pool Clown]

I have Purex Triton Minimax 350 heater which wasn't used much last season. I noticed it was slow to heat last season, the few times we used it. Now it won't get past 94* even after a couple hours run time.
My thoughts are to check and clean the jets to make sure they are burning correctly, and I suspect the heat exchanger may be partially blocked due to calcium buildup. My water is not particularly hard, but I would bet the heat exchanger has neven been cleaned in it's 11 year lifespan.
If you had build up on the inside or "water side" of the exchanger, the heater would probably bang or make some ruckus then shut off(overheating) and then try to start up again. If you had sooting on the outside you would get flame roll out blowing a fuse or get hi limit disconnect and again, the heater would shut off.
I've never done either of these things so any tips will be appreciated. I will try to find the manual online, and I will do some more searching here to see what others have done.
I think I'd need to remove the exchanger and dip it into a strongish MA solution to clean the scale from inside it? And you'd want a nice blue flame from the jets, similar to what I look for on my grill?

Do you have solar by chance? If it were night time when trying to heat, and had the solar turned on (would have to be manual solar control) you would be sending the water up to the roof and getting cooled by maybe 4 degrees, then run through the gas heater and warming it up about 4 degrees, i.e. spinning your wheels, and getting not much heat past a certain point. Just a thought

 

[shellsingleton]

I didn't get a chance yet to verify that it runs constantly, will do that late tonight after the fam's gone to bed.
I don't have solar. Wish I did, I think it would do alot to extend the season this far south.

 

[anonapersona]

When you turn it on but do not put the blower on, are there a lot of bubbles in the spa?

We recently fixed a suction side air leak that kept the heater from staying on and heating.

 

[shellsingleton]

I don't have a blower, the jets pull the air in with my setup. Water pressure, etc seems normal. I will get out there in a few and see if I can't clean the burners/verify continuous operation.

 

[anonapersona]

In our case, although the first sign of an air leak was unexpected bubbles in the spa, we also saw a lot of bubbles in the site glass at the pump. There should not be any bubbles there.