Methods for Heat Exchanger Cleaning?

Plumdog_2

Anybody developed a "better" way to clean the Gianonni heat exchanger? Been doing a lot of these lately, some that have never been serviced in years. Cleaning agents? Getting scale/crud from between the coils is tedious and time-consuming; sometimes the credit card tool just isn't stiff enough to push the baked-on crud out, so I resort to a metal blade. Gotta be a better way!

Mark Eatherton

Hydraulics...

PD, I took a 1/4" piece of soft copper tubing, and smashed it flat using a pair of Channel Lock pliers, then I cut it with some side cutters tight at the crimp, then set it up with a 3/4" N.H. X 1/4" compression fitting so I can use it to "pressure" wash the insides of the heat exchanger. It generates a real fine, knife like spray that seems to be pretty effective for getting between the sections of the Gianonni style exchangers



I use CLR first to soften the crud before manually cleaning the exchanger.



Most manufacturers don't want you to use metal because you could get metal deposition from the blade to the HXer and cause a dissimlar metal connection that may cause the HXer to fail early. I have yet to discover a plastic bladed putty knife, but will keep looking.



I know that Lochinvar and others have a "service kit" but am not sure what all it contains. I know that over in Europe, there are numerous manufacturers of pressure washing equipment for HXers (inside as well as out) but have no experience with them either.



I wrote an article a while back for Contractor Magazine on this topic, but can't seem to access their web site right now. www.contractormag.com



WIll be interesting to see what others are doing. Always a better way to skin a cat...



ME

tim smith

Re: Giannoni heat x cleaning

Mark and Plumbdog, I just was talking with one of my techs about the method Mark mentioned. He uses a copper tube and valve on hose but had not flattened end for a real fine spray. He has worn out old credit cards, store cards etc he uses to get between the coils and then flushes the  you know what out of it. But we still have a tough time getting all the debris out of the collector pan. I think the fine spray blowing down between coils will help to dislodge the debris in base of pan so it will flow to trap where we tape our wet vac to it to suck all the water and debris out.  We service probably 100 plus a year of these and are pretty adept but always learning better ways. Tim

Charlie from wmass

Plastic putty knifes

all the hardware stores have them for $1-$2 a piece. I was told spray it down with mineral oil and then fire it briefly, then rinse. I will be using Marks idea. I had bent my tube at a 90 and pinched the end mostly closed.

Slimpickins

Target wall

Just wondering if you guys are removing the target wall before cleaning? 

Plumdog_2

Target wall comes out!

Slim, you gotta remove the target wall; but they come out pretty easily. Good idea to have a new one in the parts box....I've seen them crumble when the condensate drain is clogged and the heat exchanger fills up. It will also crumble the burner door "molded ceramic fiber disc" and could corrode the screws below the water line so badly they will break off! Not good. I will try Mark's bent-tube fine spray idea....I have something similar for blasting compressed air downward thru conventional burner tubes without pulling them from the burner tray; for a quick dusting. Also gonna look for a plastic grout-saw type tool or make one. 

Slimpickins

comes out easily?

I usually take out the target wall and its not easy to remove the retaining screw that holds it in place. 7 out of ten times it's in tight and I usually end up stripping the head of the screw. If there is a trick to removing it, please share.

Steve Whitbeck

cleaning

I don't reccomend using anything but water on the heat exchanger.

I remove the refractory and then vacuame the crud out, then I brass wire brush the crud off of the tubes. I then wet it and brush it again. Wetting it will loosen up the crud, I then use a metal feeler guage to push the crud from between the tubes. The last thing I do is wash the exchanger and flush the drains. ( kneed the drain hose to break up the crud ) I have a hose with the end cut off and push this against the tubes and this forces the water to go between the tubes only.

I NEVER use any chemicals. I have seen too many bottom pans rotted out from using acid.  Running on LP creates a coating of crud inside the bottom pan up each side from 4 oclock to 8 oclock with the bottom at 6 oclock clear. This coating of crud soakes up the acid and concentrates it against the bottom pan. I have cut open more than a few of these heat exchangers.

icesailor

Feeler Gauges:

Steve,

You do know that they make brass feeler gauges? They come on a really good set of feeler gauges with Stainless Steel gauges. I think I got my last set from Sears but McMaster-Carr might have them.

Also, you might try looking for someone who has pieces of 304 or 404 stainless steel. 404 is harder than the tar road. You need Cobalt bits to drill it but you could attach it to a handle and use it between the tubes. 304 and 404 is more nickle than steel so there shouldn't be any problems with the SS type in the HX.

Anyone, please correct me if I am wrong. It may be a bad idea.  

NYplumber

NTI Tinity wand

NTI sells a wand to clean their Trinity boiler. I came across this cleaning manual after a local supply house tried to sell me on the new NTI Trinity firetube boiler.

The down side to the wand is the need for a pressure washer. With all the other tools such as CAs, manometers, compressors, impact drivers, wetdry vacs, ir cams, jack hammers, who has the money to start adding pressure washers to the trucks, not to mention the extra care for them if you live in freezing climates, which we all do, hence the need for the boileres we are there cleaning.



http://www.nythermal.com/pdfs/Cleaning-TrinityCombustionChamber.pdf







On a side note, what do you guys think of this boiler?

icesailor

Heat Exchanger/Sulpher

That heat exchanger looks like a cold start oil boiler running non-low sulpher oil.

Is this what you are getting with condensing boilers on Nat Gas?

Bad.

AFred

NTI

Stay away from them.

-Andrew

Steve Whitbeck

Alfred

Why stay away from NTI?

AFred

The Past

The shop I work for put alot of Trinitys in years ago, and I/we maintain quite a few of them.

1: Here in minnesota I have a hard time finding parts readily available.

2: When the parts have to come from the factory(in canada). It usually takes ~10 business days.

3: I have had the factory send out incorrect parts.(thats a long wait for the parts)

4: Apparently we are not the only shop who has had trouble with NTI standing behind their warranty

5: Mission coupling on the exhaust. In time they all leak.

Still after I clean/fix 'em up, they run dang efficient! I am sure this new fire tube boiler is great. The HX is the right way to go. I just can't look my customer in the eyes and recommend NTI. I'm sorry if I stepped on anyones toes, I just have not had good luck with them.

-Andrew

BobC

Replacement for cridit card

I worked in electronic manufacturing for most of my life and discovered the fiberglass circuit board stock (G10) to be real good for this kind of application. It comes both plain and copper clad. The material is stiff and abrasive at the edges, it is almost impossible to wear out. It comes in thicknesses from 1/64 up to 1/8 and beyond, sounds like 1/16 or 3/32 would be what you want.



If you know anyone who worked in this industry they probably have scraps of this laying around because it comes in handy for many applications



Bob