Belmot DV Pilot Pipe Leak

[JBCat]

I have been pulling my hair out with a problematic install that I did last year.

I installed a monessen blemont 500 last year and at times, the pipe seams on my horizontal runs will drip water. The pilot will also drop out after 5-10 days of no use. I may have exceeded to horizontal run by accident but the unit works fine when in use.

My thaught is that the moisture from the pilot is building up in the pipe untill all of the oxyegen is gone and then the pilot drops out. When burning, the FP will create the draw to run ok.

Has anyone else seen this??? Tech support thinks the water is from outside but I dont buy it. Also the term cap is a snorkle by simpson.

I may have to tear the who unit out if I cant find a solution.

[SeattlePioneer]

Sorry, I find your post too vague to provide any useful reply. Where exactly is this leak or condensation occurring?

Is this natural gas or propane?

Have you checked to see if any water is entrained in the incoming gas supply?

Is there any indication of erratic operation of the burners on other gas appliances?

I don't understand your comment about the oxygen being depleted at all.

[hearthman]

If you exceeded the horizontal offset, you must shut it off, tear it out and reconfigure it to meet the listed instructions. Failure to do so may hinder performance, lead to early failure of components or increase firebox temps. to where the clearances are no longer valid so it poses a fire hazard.

Snorkels are difficult to properly seal to the ext. wall. You can get water from the termination that drains back towards the unit. If you see water dripping from the outer pipe casing, it most likely is rain from the termination but could be condensation of building humidity. You pilot theory holds no water (pun intended). The tiny amt of moisture created by just a pilot is more than absorbed by the ever flowing air through the outer concentric ring of the direct vent pipe through the combustion chamber and out the exhaust. Any tiny trickle that might condense in the inner pipe will most likely get vaporized when it gets near the combustion chamber.

Where are you seeing these drips? Is this pipe pitched 1/4"/ LF?

[JBCat]

The unit is Nat Gas

The water seems to be comming from the pipe joints. I do not see any evidence of waterfollowing the pipe on the outside.

When in operation, it works for about 2 - 3 hours but the customer says the unit will shut down and the pilot goes out. I have not been able to get the unit to do this...I have concluded that this is maybe from a dirt because of the amount of construction still going on.

I will try to post a pic today.

As far as the horizontal run, at first I pushed the unit out of spec by having too many 90deg because I forgot to account for the snorkel being a 90. I had to reconfigure with 2 - 45deg in order to stay at my spec. Igave the spec to monessen and I now meet spec but I will admit that it is close.

When I first looked at the job, my gut told me that it would not work. The moreI looked at it though I changed my mind. I need to listen to my gut more.

Thanks - JB

[SeattlePioneer]

Ahh. You were talking about the vent pipe. I was imagining you were talking about water on the incoming gas supply.

Sorry.

[JBCat]

Pic 1 is an overview with the pipe termination going right of the FP above the drop ceiling.

Pic 2 is one of the leaks..I have never seen water comming out but you can see the stain.

Pic 3 is the snorkel termination on the outside of the building.

[hearthman]

JB, that pipe looks level yet the listing requires 1/4" per LF slope. Does it?

That 18" horizontal ell derates your max. horizontal offset by 18"---did you figure on this?

The way that snorkel appears to be cut into the siding is asking for trouble. Never rely on just caulk to stop water. All caulk will eventually fail.

Finished unit looks nice!

[JBCat]

I cut the siding (wood) and then slid the cap up tight so the metal flange is under the bottom board. My thought is water goes down the siding and then on top of the cap and then rolls off. The sheathing was caulked prior to putting the cap on. The sides are also caulked. If it were vynal I would flash with J channel. Im thinking about pulling off the snorkel and putting a regular cap on to see if things chang a bit. I did figure the 18" reduction but it also adds to my vertical height. But I agree that the 18" reduction may be worse than the 18" height. If I did not follow an exact 1/4 rise then would I notice a problem durring the burn???? It was really hard to measure but I used a leevel and it does head upwards. The main problem is when the unit is sitting not in use with the pilot burning. I would think that if venting rise was a problem then I would notice ghosting in a short period of time.

Thanks for you help. Just when you think you have got a grip on this industry, something like this brings you down to reality...JB

[JBCat]

I am considdering changing the exposed pipe to flex in order to reduce a 45 and to shorten the horizontal length. Been talking with monessen and this unit was just approved for flex venting. Hearthman, what do you think??? Thanks JB