Pentair Mastertemp 200 heater doesn't ignite

navis

Member
Nov 25, 2017
12
Temecula
Hi Y'all,
New to the pool equipment repair world, so I've watched a ton a videos, and am trying my best to repair my Mastertemp200 that won't heat. I've already watched 2 dozen videos, and made some progress, but now I'm stuck about what to replace next. Started with replacing the Thermistor, which fixed my "126" error on the eternal LED panel, but then the Service Heater Light came on. Started taking it apart, and found that the AFS light was turning on, and the blower motor was not spinning. I removed the blower motor, and cleaned that sucker out, it was full of while crystal deposits that prevented it from spinning. After cleaning it out, and lubing the motor, the blower seemed to spin with ease, so I put it back and reconnected everything. The afs light still comes on, but the blower comes on and seems to spinning vigorously, so I think I have the blower working as needed. Here's where I'm stuck. Not sure what to check next. Currently, the symptoms are that the AFS light comes on almost immediately, even before the blower starts up. If I bypass the AFS by jumping the connections, the AFS goes off, the blower continues to run, and I hear an audible click about 8 -10 seconds into the startup cycle, but I don't smell any gas, and the heater never seems to come on. What should be the next few things to check? Any advice would be appreciated.
 

JamesW

TFP Expert
Mar 2, 2011
21,148
Remove one of the bottom manifold bolts to see if water comes out.

I suspect that you have a leak in the heat exchanger.
 
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navis

Member
Nov 25, 2017
12
Temecula
The heat exchanger is leaking. It's not worth replacing, in my opinion.

How old is the heater?
5 years. Thanks for your advice. its a mastertemp 200.. .I see prices around $1800... I see heat coils for $600. Do you feel that its not working replacing because it's too difficult, or not likely to work? Seems like if I could replace it and save $1200, it might be worth the attempt, no?
 

JamesW

TFP Expert
Mar 2, 2011
21,148
What is the manufacturing date from the sticker with the barcode?

You can replace the heat exchanger if you want. There are several videos on Youtube that show the process.

If the heater is only 5 years old, I would want to figure out why the heat exchanger has failed before I spent any money on repairs or replacement.

Usually the damage is due to water chemistry or a nearby tab feeder or excessive water flow.
 
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navis

Member
Nov 25, 2017
12
Temecula
What is the manufacturing date from the sticker with the barcode?

You can replace the heat exchanger if you want. There are several videos on Youtube that show the process.

If the heater is only 5 years old, I would want to figure out why the heat exchanger has failed before I spent any money on repairs or replacement.

Usually the damage is due to water chemistry or a nearby tab feeder or excessive water flow.
I can guarantee the problem resulted from my poor water chemistry habits... tough lesson.
 

JamesW

TFP Expert
Mar 2, 2011
21,148
Correct, the Tube Sheet Coil Assembly Kit. It's a big gamble if it needs more than the heat exchanger. Here's a video of what to expect. It's a 400 model but basically the same thing.

 

navis

Member
Nov 25, 2017
12
Temecula
Correct, the Tube Sheet Coil Assembly Kit. It's a big gamble if it needs more than the heat exchanger. Here's a video of what to expect. It's a 400 model but basically the same thing.

yeah... I saw that video.. smh.. not sure what I'm going to do. To provide a little more info, after I drained the water, I replaced the bolt, and fired it up. This time, the afs light didn't go on, the igniter clicked, and I felt a blast of warm air from the heater duct and the heating light went solid. However, it only lasted a few seconds, and then the light went back to blinking. It did this twice more, than the service heater light came on. Does this provide any more information that might determine why you think I should do? Buy new vs attempt heat coil repair?
 

JamesW

TFP Expert
Mar 2, 2011
21,148
It's a big gamble to buy a heat exchanger.

If it works and you get several years, you win.

If not, you will probably wish that you didn't put the money into the new exchanger.

Your call.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
17,382
Tucson, AZ
Bad water chemistry that causes a heat exchanger to rot out is going to cause other problems as well. All of the components in the header/manifold (HLS, thermistors, thermal regulator, etc) have been in contact with that same water. You could easily wind up with a cascade of failures after getting the heat exchanger replaced simply because good components are now mixed with compromised parts. It could turn into a "chasing the rabbit down the money hole" situation.

My opinion - I would short-circuit the grief and aggravation and just get a new heater. You could even upgrade to a MasterTemp 400 (assuming your gas line can handle it).

But, after pushing the "Purchase" button, I would encourage you to do a deep dive into your pool water chemistry and figure out how to take care of it better. Otherwise, you'll just wind up in the same situation again....
 
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navis

Member
Nov 25, 2017
12
Temecula
Thanks guys.. I guess I will just go the new heater route... I really enjoy problem solving, and was making progress, so it is sad for me to give up now... but you guys make a lot of sense, and given your "expert" status, a newbie like me should just listen to the good advice. As far as pool chemistry... the problem is with the lazy guy who takes care of the pool (me). I have learned why its important not to let it go months without chlorine other than the battle with the green pool...:p
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
17,382
Tucson, AZ
A green pool (algae) isn’t going to damage a heater core. Low pH (acidic) water got in there and ate away at the copper from the inside out. As @JamesW alluded to, very high flow rates of water through the heater can cause physical erosion of the copper as well.

Are you adding any chemicals through skimmer or using stain treatments like ascorbic acid?
 

navis

Member
Nov 25, 2017
12
Temecula
Update... I put in a new heater (Pentair MasterTemp 250).. works great, but now I tested my pool and my copper measurement was 3.6! Seems that JoyfulNoise was right. Now, Im in an epic battle to get my PH up, and my copper down.. sigh.