Munchkin spark electrode

Steve_56

I recently starting getting an F09 error and the boiler won't fire. I cleaned the combustion chamber per the instructions, reassembled, and the boiler lit, but only for the night. Now I'm getting the F09 error again.



To help isolate the problem, I have a silly question. If the spark electrode is firing, should I be able to see a spark through the viewing window? I hear a buzzing which I assume is the electrode firing, but can't see any spark.



Boiler was installed about 4 years ago and has been working flawlessly until now.



Thank you

BobbyG

more information

did you clean it after you started getting the F09 fault codes?  If you did, what did the inside look like?  any "coffee grounds"?

the clicking you hear is the igniter.  do you actually see a flame before it goes out?  F09 means there isn't flame sensed - doesn't mean there isn't a flame.  It tells us whether it is a flame sensing problem or a ignition (gas, igniter or otherwise) problem.

we'll start with this.  Which direction do we take: flame sensing or ignition problem.

BobbyG

not firing

not firing

1. take the igniter out of the unit (temporarily for diagnostic purposes only) and see if it will externally spark.  from the clicking sound it should be....if your condensate trap isn't draining properly, moisture will be in the combustion chamber and the "spark" will jump off onto the insulation instead of out the point where it is supposed to spark.

did you clean the trap out too?  Is the drain vent still open?  on the older units the condensate drain hose connection had a tiny hole in the fitting for venting, this hole should be free and clear to help the unit drain properly.

2.  clicking - can you hear the gas valve click open? - do you smell gas out the exhaust vent, when it doesn't light and the blower blows it out the vent pipe?

Steve_56

leak

Thanks to both for the good advice. I checked the spark electrode externally and it is sparking, and was also able to smell the gas when I did this (since the electrode hole was open). Also, FWIW, I did have a good amount of "coffee grounds" when I cleaned the unit.



I checked the condensate hose, and noticed it was dribbling (which I thought was odd). So on a hunch, I turned off the auto-fill valve, and the system pressure slowly dropped, so I have a boiler leak. Any recommendations on the usual suspects? (do those coffee grounds damage the heat exchanger? It didn't look bad once it was cleaned)



Thanks again,



Steve

BobbyG

water leaking

does your relief valve tie into your condensate drain line?  Make sure your relief valve isn't opening (spring gets weak) and that is what you are seeing.



If that checks out, check all of the heat exchangers openings (sensors, hi-limit, eco switch) by gently peeling back the insulation and shining a flashlight to check for small leaks.  It may be easier to "dab" a brown paper towel around the openings (to see the water).

Steve_56

leak

I opened up the boiler chamber again, turned pressure back on to my system and the leak was apparent. A pinhole leak at the top of the chamber. Any suggestions what to do from here?

Mark Eatherton

Not much choice in the matter...

The heat exchanger needs replaced. Hopefully, under warranty.



If I were you, I'd contact the installer, if you can, and start arranging to have it replaced.



If you can't locate the original installer, contact the manufacturer and see if they have another dealer in your hood that can handle the replacement for you.



Don't EVEN think about using a stop leak product, or you will experience a catastrophic failure due to HXer melt down...



Bummer.



ME

Unknown

The Great ME speaks,,

in this case he is right,,,, Giannoni HX  are adopted to many units,  however longevity applies to us all.

Personally, I dislike this design, but we had to start somewhere.

Replacing after 4 yrs. would tick me off to no end,, then I would wonder how long the replacement would last.



Nothing personal Mark,, just a statement.

Steve Whitbeck

Munchkin

Munchkin will replace the boiler - the installer will have to pay for the new boiler but will get a full refund for the cost of the boiler.

I bet that your boiler is vented with a concentric vent - if it is then you MUST modify it so that you have at least 18 inches of vertical seperation between the exhaust and the intake pipes.

Exhaust gas reversion causes very high acidity in the condensate and it eats up the stainless heat exchanger.

When you clean the heat exchanger you also need to clean between the fins with a feeler guage and then take a rubber hose and spray between the fins to clean the bottom pan and flush out the drain lines.

Slimpickins

Worth noting as well...

Giannoni heat exchangers do go bad, sometimes it's a manufacturing defect, most of the time it's a installation problem. Do you have the correct primary pump and is it piped in a true primary/secondary arrangement? Was the combustion set up when the boiler was commissioned with a combustion analyzer? Over firing combined with low flow would cause your problem. I would also check your water chemistry and make sure it's in range that's listed in the installation instructions. Definitely things to address before replacing unit. 

Slimpickins

one more thing

You shouldn't use a feeler gauge to clean between grooves of the exchanger. I  would use an old credit card or grocery store card, something that doesn't scratch the stainless. 

Steve_56

install details

Thanks again for all the tips. The unit is not exhausted concentrically, the exhaust terminates about 3ft from the intake.



The unit is definitely plumbed primary secondary, so I don't think there have been any flow tests.



However, I am not aware of any combustion analysis being done on the unit, or any water chemistry being checked either.



I will keep all of this in mind when installing the new unit, you have all been a big help. Now I have to figure out how to contact Munchkin/HTP.

Jr_12

Boiler

The entire boiler will need to be replaced. Is that green material in the heat exchanger? That would be an obvious sign of re-circ. Sometimes 3ft is not enough depending on the conditions. I've seen 399's exhaust drop 6ft straight down into the intake in certain situations. Best bet would be to sit outside and watch the exhaust for a bit. I don't see dis-colored coils so I wouldn't think this to be a flow issue. Typically you would have darkened coils if it were a flow issue.

Also, a brass or nylon brush would be better than a credit card or feeler gauge to get between the coils.

.02

Steve Whitbeck

feeler guage

The factory recomends a feeler guage.

You will never get a credit card between the tubes it is too wide unless you cut a 3/4 inch strip off and then it will just bend.

I vacuame out the coffee grounds and then I use a brass bristle brush, then I use the feeler guage. Get a brass one if you are worried. Then I water wash between the fins with a hose with the end cut off pushed against the tubes.

ErikV

cleaning the Hx

A heavy nylon brush on a drill mount (according to this forum), CLR (according to HTP manual), flush liberally (according to common sense). Works great. See previous post e.g.



http://72.3.142.104/forum-thread/128833/Munchkin-Contender-Heat-Exchanger

Slimpickins

sticking to what I said

I went to a class about 5 yrs ago on cleaning Munchies put on by the factory rep. They said use an old credit card for the condensate weep slots and it works just fine. Also, Rydlyme works so much better than CLR and all I've needed was a nylon vegetable brush along with the credit card. I've cleaned well over a hundred or so of  Giannon's that I've developed a French accent. 

Steve Whitbeck

5 year old training.

The latest factory training is to use a feeler guage.

And I don't use any acid. Rydlyme will attack the stainless steel. I only use water and the brass brush.

Have you ever cut open a G heat exchanger - I have cut open about 5 of them to date and ALL showed pitting of the bottom pan. The worst ones looked like swiss cheese when held up to a light. Those were cleaned with acid and were running on LP.

Jr_12

Hold On

The pitting found on the bottom shell is due to recirc or chemicals coming in through the combustion air! They have nothing to do with Rydlyme/CLR being used! You can clean exchangers with just water and a brush, but it's still easier to use a cleaner to help the process. Go a head and use a feeler gauge if your comfortable using it, but just don't scratch the stainless with it.

Steve Whitbeck

The Point IS

You don't need any cleaner to get it clean. Just use the brass brush and straight water. Recirc gasses cause much higher acid content in the heat exchanger. Acid in any form that is stronger than what is normally there will cause erosion of the bottom pan. Put some Rydlime on some stainless steel and see what it does.

You will stop using it when you see what it does.