Heating Help

Munchkin Contender Heat Exchanger

The attached pics are from a MC-80 installed 2 yrs ago. That heat exchager took a beating. Took the pics this morning.

Low flow?

Would you suspect that low/no flow condtions caused the deformations in the heat exchanger? and if so, wouldn't the high limit kick in before such damage could be caused?

Munchie

It may be a low flow situation and an over fired condition. Is it pri/sec pumped? Combustion analysis?

This was brought In

An thrown on my counter this morning by a contractor. Looks like it was dry fired a few times by the twisting. I'm thinking that the condensate had no where to run. It leaked onto the control and fried that also. Sending it back to Munchkin..I'll let you know what they think.

looks normal

Tough to tell from your pics but to me it looks normal  . if tubes are burned they  be brown color  the shape looks normal too  as well as debri and colors for a boiler that may never been maintained  . I dont know what happen to your control. 

Normal?

If this is normal and the gaps are gone between each coil in the exchanger where does the condensate go?

I agree. Looks normal to me...

Looks like every Giononni heat exchanger I've ever seen.

I spoke with the chief engineer for HTP a while back about the use of a carbide impregnated nylon stripper brush for cleaning these things up, and he said he couldn't see a problem. The one I use is orange, and from a company called Nylox, and when you are done, it looks like brand new.

THe condensate can get between the sections, no problem. It is not exactly like the Viessmann, where you can slip a credit card between each perfectly formed section. If memory serves me correctly, this company uses hydraulic pressure (internal) to deform their heat exchangers, and it is not consistent or uniform in its production.

ME

Mark did you purchase that

brush in your area or is it something available elsewhere?

Home Depot...

But last time I was there, tried to find one and couldn't.

Don't know whassup widat...

ME

How about a drill mount nyon brush

for cleaning the coils? Seems a way to get abrasion without damage.

Nylox or Nyalox?

OK maybe drill mount is implicit in your post, newbie here ...

I found Nyalox at local Ace hardware. They had Blue (fine) Orange (coarse) and Black (very coarse). Unsure if it was the right product I went with blue to err on the side of caution. Seemed to clean without damaging the coils, although it is not "good as new." I used it on an old 1200 rpm drill.
Brush, coils before, coils after:

Best

plug for Viessmann I've seen lately!

Viessmann Heat Exchangers?

So how well/long  does a Viessmann heat exchanger keep before a good cleaning is necessary? I'm also puzzled by what looks like rust spots on the Munchkin heat exchanger. Was it previously cleaned with a regular ferrous type brush? 

Of course

a Viessmann HX needs regular maintenance.I don't expect to see this type of deformation with a Viessmann,however.Superior design,materials and construction in comparison to a Giannone

Looks like a Knight I just cleaned...

The "deformation" (or formation) of that heat exchanger looks very similar to a Lochinvar Knight KBN 399 (2 of them) I just cleaned recently, obviously b/c they are both Giannoni heat exchangers. So it must be normal. That little dip by one of the coils is where it goes into the lower condensate secondary heat exchanger is it not?
Also, any of you guys used chemicals to clean these heat exchangers? I know they are not recommended but the interesting thing is the local Lochinvar Rep, after telling him what PITA it was to clean all the crud (probably sulphur) off of one of the Knights, suggested using a Brass brush, which shocked me a bit, yet we can't use chemicals? (i.e. Citrisurf 3050 or CLR)?

Munchkin manual says to use CLR,

do other vendors/manufacturers recommend otherwise?

double post whoops