Mastertemp 400 Shutdown Issue & E05 error

JamesW

TFP Expert
Mar 2, 2011
16,384
The part that was in the heater was probably from one of the top tabs of a grid where it goes into the top manifold.

If you took the grids all apart, I suspect that you would find one or more pieces missing.
 

freebsdrules

Well-known member
Sep 3, 2019
55
delaware
That makes sense. Unfortunately, I did not take apart all of the grids. Cleaned it up though, put back together, added DE, and the heater is presently running as a test. Woo hoo!
 
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JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
15,810
Tucson, AZ
This is an excellent thread, thank you for posting it. Gas heaters can be a real mystery to figure out sometimes and having these types of quick checks and diagnostic information really helps. Paying a service tech to come out for a heater can get real expensive, really fast. Anytime you DIY the repair, it’s big $$$$ saved.
 
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freebsdrules

Well-known member
Sep 3, 2019
55
delaware
This is an excellent thread, thank you for posting it. Gas heaters can be a real mystery to figure out sometimes and having these types of quick checks and diagnostic information really helps. Paying a service tech to come out for a heater can get real expensive, really fast. Anytime you DIY the repair, it’s big $$$$ saved.
Couldn’t agree more. I’m not the handiest person but love to at least try to DIY first. Saved some $$ for sure!
 

JamesW

TFP Expert
Mar 2, 2011
16,384
Glad that it worked out for you.

Hopefully, it will work now without further problems.

When you get a chance, you should do a full breakdown of the filter and clean and inspect the grids.

If more parts break down, it can cause more heater problems.

The grids have already been replaced once, but they can be damaged by poor chemistry.
 

freebsdrules

Well-known member
Sep 3, 2019
55
delaware
Glad that it worked out for you.

Hopefully, it will work now without further problems.

When you get a chance, you should do a full breakdown of the filter and clean and inspect the grids.

If more parts break down, it can cause more heater problems.

The grids have already been replaced once, but they can be damaged by poor chemistry.
Thanks, I'm hoping. I was trying to avoid replacing the heater and I'm glad I did not as it seems that was just a symptom/casualty of other problems. I think I'm going to try to do a full breakdown when it's time to close the pool this year. That way, we can start clean next year!
 
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freebsdrules

Well-known member
Sep 3, 2019
55
delaware
Glad that it worked out for you.

Hopefully, it will work now without further problems.

When you get a chance, you should do a full breakdown of the filter and clean and inspect the grids.

If more parts break down, it can cause more heater problems.

The grids have already been replaced once, but they can be damaged by poor chemistry.
Ok, finally took the filter apart and did a full breakdown of the grids this time. Cleaned and inspected and nothing appears to be broken. I'm going to put it back together and call it a day and hope there are no further issues. Any other thoughts on what might have gotten into the heater??
 

JamesW

TFP Expert
Mar 2, 2011
16,384
It looks like one of the top tabs that insert into the top grid manifold. Are you sure that none are missing?

Maybe from an old grid and the piece was rattling around in the heater inlet for a long time before finally getting wedged in the plunger assembly?
 

freebsdrules

Well-known member
Sep 3, 2019
55
delaware
It looks like one of the top tabs that insert into the top grid manifold. Are you sure that none are missing?

Maybe from an old grid and the piece was rattling around in the heater inlet for a long time before finally getting wedged in the plunger assembly?
I'll go triple check but that's the first place I looked. Nothing broken. The pool company did replace filter grid(s) the first time we opened the pool with them but I can't remember the reason they gave me they needed to. Certainly possible it had been in the "system" for a while and just now got stuck.

(edit) just went to triple check as I put back together and indeed, nothing is broken...
 
Last edited:

freebsdrules

Well-known member
Sep 3, 2019
55
delaware
Ok, I suspect that the piece was probably in the heater for a while.

Hopefully, you're in good shape now.

:goodjob:
Thanks and I hope so! I spent more time on all of this than I wanted to but I learned a TON (thank you all) and certainly saved a lot of money too.

As for the fitler grids, aside from obvious breaks/tears/etc., when and how do you know you need to replace. As stated earlier, ours are finishing up their 3rd season.
 

JamesW

TFP Expert
Mar 2, 2011
16,384
Under good conditions, you should be able to get about 10 years out of a set of grids.

Mostly, look for any obvious damage.

Also, watch the returns carefully for a few minutes when you add DE. If there's a problem, you will see DE coming from the returns.

If everything is working properly, the return water will stay crystal clear.