anyone know what this build up is inside heater?

plsbcheap

Well-known member
Jun 24, 2007
75
I am just curious. I am having heater problems (Pentair MiniMax see other posts if you can help) and while taking the cover off I noticed this residue.

Any on know what it is?? And does it effect anything? Should it be cleaned out? Notice it is on the back wall in the photo too.

 
G

Guest

Since you have a SWG it could be salt or it could be scale.
Does it dissolve in water?
If not does it dissolve in diluted muriatic acid along with fizzing and bubbling?
 

DeltaT

Active member
May 20, 2008
29
upstate, SC
hard to tell from the pics, could be a few things, Insulation thats lining the walls of the heater falling down on the burners. Definitely get it looked at and cleaned up dont want that stuff clogging up the burners(more than likely). Also could be a by product of incomplete combustion although there seems to to be way to much of it for that. Does it feel fluffy or gritty. Either way I'd have a HVAC company look at it
 

plsbcheap

Well-known member
Jun 24, 2007
75
waterbear said:
Since you have a SWG it could be salt or it could be scale.
Does it dissolve in water?
If not does it dissolve in diluted muriatic acid along with fizzing and bubbling?
I have never seen a leak (even a drip) in or around the heater. Even though my heater power is off right now, water still flows through the heater and it is dry underneath there. It is very light and fluffy and will break off very easily. Almost like calcium, salt and "airy foam" but it also looks kind of like the "christmas snow" you spray on trees. When broken off it will disenagrate into dust when you step on it or squeeze it in your hand. My gues is that it will disolve with water but I have not tried that.
 

plsbcheap

Well-known member
Jun 24, 2007
75


Here is a larger/closer look at the flutes. It is actually the first two and the last one on the far left (that you can't see). None of the ones in between and I think only on this edge (that you can see). None further back in there. The pan underneath has some drips on it too.

Notice the back wall. Is that insulation? It is soft too but kind of uniform accross so I wondered if it was insulation with a thin film of this white stuff covering it.
Thanks,
 

duraleigh

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Apr 1, 2007
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My propane (not natural gas) house heater has an almost identical residue that is a by-product of the burn.

As the exhaust moves out of the burner area, there is a cold air intake used to cool the exhaust emp. This residue builds up and falls almost directly under this intake.

Can you look up directly over the residue and see if your exhaust stack is directly above that area and, most likely, an opening where cold air is allowed in?

Convoluted explanation, I know, but if it's directly underneath the exhaust stack, I believe it is a harmless byproduct of the burn.

I sweep or wipe mine up probably once each year.
 

spishex

TFP Expert
Oct 12, 2008
1,375
Hillsborough, NC
It's building up right underneath the insulation panel on the back side. And guess what I happen to have sitting outside right now? An old minimax insulation kit. Let's take a look:

This is what the insulation paneling looks like. That panel to the left is the short one that's sitting just above the burner tray, right where that build up is accumulating.
[attachment=1:2c5neihd]IMG_2446.JPG[/attachment:2c5neihd]

Here's a look at the material itself. Feels like cotton candy when it's dry. Once it's been wet and cooked, not sure what it would be reduced to. Some of the crustier bits did have a crumbly consistency to them.
[attachment=0:2c5neihd]IMG_2445.JPG[/attachment:2c5neihd]

I wonder if you've got something trying to make a home in your insulation? Mice do it to hot tubs all the time. It's not really a fun job breaking the heater all the way down to this panel, but nothing complicated and it would probably solve the mystery. Or you could clean it off, fire up the heater a few times and see if it comes back.
 

Attachments

plsbcheap

Well-known member
Jun 24, 2007
75
3 more photos to explain this mystery further. I asked the Pentair guy on the phone today and he didn't seem to think it was anything abnormal. :eek:
The first photo shows some of the stuff in my hand. It is so light and just crumbles into nothing / dust when you pick it up. I did check it by dipping my hand in water and it dissolved almost immediately.


The other two photos are from a friend of mine who has a Pentair Minimax NT also. I was working on his today and took these photos. While his build up is not near as heavy as mine was, it is still there. That made me feel a little better. I used a mirror and looked up from the burner and it looks like it is coming down the walls (coating the insulation) and dripping onto the edge of the burners. Any other ideas?






Let me know if you have more ideas just for curiosity. Thanks,
 

DeltaT

Active member
May 20, 2008
29
upstate, SC
waterbear said:
sort of looks like asbestos!
Pretty much what it is( its not stose but its replacement the name escapes me) fire resistant insu to keep the heat in and the box cool, you need to get it cleaned up, find out why its breaking down, most likely cause condensation build up from a venting problem or improper burn. You don't want that stuff on the burners. It can cause all kinds of probs
 

plsbcheap

Well-known member
Jun 24, 2007
75
spishex said:
It's building up right underneath the insulation panel on the back side. And guess what I happen to have sitting outside right now? An old minimax insulation kit.

Here's a look at the material itself. Feels like cotton candy when it's dry. Once it's been wet and cooked, not sure what it would be reduced to.

It's not really a fun job breaking the heater all the way down to this panel, but nothing complicated and it would probably solve the mystery. Or you could clean it off, fire up the heater a few times and see if it comes back.
It is not asbestos. It is likely some sort of after burn. I'm not sure how it could be a venting problem. It is out doors and blows out like every other minimax. It crumbles and feels like very light sand in your hand (when crumbled with smallest squeeze) and then dip you hand in water and it dissapears. A damp brush washes it away. It is not like cotton candy or insulation. It has actually coated the walls over the insulation with a thin film of this stuff like ice on a bad coil for A/C. I'm tempted to taste it :shock: cause it looks like salt or calcium. But I don't think calcium would disolve so easy. It definately slides down the wall and drips on the edge of the burner. I really have not used the heater that often. Just for the spa probably 25 times.

A mystery..... :?
 

DeltaT

Active member
May 20, 2008
29
upstate, SC
When its not burning properly you can get a "white soot" by product of incomplete combustion. But there seems to too much of it but its hard to tell from pics