Munchkin HELP ?

N.S

I have installed over 20 m199 but this is my first m80.On low fire I get a harmonic hummmm , It then progresses to a loud baffeling sound.This only happens on low fire.Gas pressure is 8" WC.I have good GPM flow.Venting is a short 5' run.I have ajusted the CO to approxx 10 ppm on low fire.
But the reverb happens no matter where the co is set?

Questions. Do I have to go vertical for 18" first on the venting ?.How far up the venting are you to drill the test hole ? What are you guys useing to plug the test port in the pvc venting after you are done ? Could the baffeling be the new gas meter cant handel such a low demand and it starts to reverb, is 8" wc on the low side of proper operation.Or could the plumber have undersized the gas line ?

Noel

Unknown

(not the same Noel)

You might pick a different way to call yourself, here.

They might confuse you for a Slant/Fin Tech service rep, by the same name, that doesn't work on Munchkins.

Noel

Rich S

humm

Change the gas valve.

Setting is off.

Factory adjustment.

Guy_5

Munchkin

Actually, we can make some field adjustments that will solve this problem.
Give me a call at 800-323-9651 Ext. 157 and I will walk you through them.

Guy

Jim Kreger

Same Hmmmm problem

Just installed a pair of M140's today and one started up with the same symptom, only at the low firing rate. Other unit is fine. Sounds as if it is an oscillating flame and LPG gas smell gets real bad....coming from the air intake. Help is appreciated. jimk

Chuck Shaw_2

Help is available

just call the number above, Guy is not in today so you can try me, or Sham or Jeff

Chuck

lchmb

can I ask

When you folk's do find the problem could you post it here? Love to learn and this is a good place to start! Thank's..:)

Pinball

I had a Munchkin problem almost the same today.Only the unit would'nt fire at all, and go off on code"F09" I called and spoke to Sham, he walked me through setting up the gas flow with a Bacharach co2 kit. The unit works great except for a bad pressure switch(unrelated prob.) It is real easy to fix. just have a short handled screwdriver handy. Also you can plug the test hole with a stainless bolt. the tech. support is great at HTP!
Thank Sham for me Chuck (you were on the phone with someone else at the time)
Al @ Advanced Radiant Design

N.S

Thanks jeff @ HTP

I would like all to know how great the support at HTP was today. I called the 800 number and got a MR. JEFF COOK on the other end. This guy stayed with me on the line for over an hour and walked me thru step by step how to adjust the gas valve and the RPMs. Every time I ran to my van or to a stat when I returned there he was still on the other end. I cant tell you how great it was to feel the confidence in that this guy knows his boiler line . I am a better man after today ( well aleast a better boiler installer )

***** Thank you very much jeff *****


Noel in Denver CO.

joshua van Tol_2

Had the same symptom with a M140

I had the same symptom with an M140. I called tech support at the supplier where I purchased the unit, and they advised (after consulting HTP) that I make an adjustment to what was presumably the mixture screw. This appeared to help a bit, but did not totally cure the problem. I noticed that it would still occur when starting from a completely cooled down situation.

The noise that the unit made, and the conditions under which it occured made me think that maybe the exhaust tubing was resonating. I had checked my install scrupulously against the install manual, and realized that I was very close to (but now below) the minimum length. I decided to test my theory by temporarily adding some length to the exhaust by holding a 4' length of 3" pvc up to the outlet of the concentric vent. This stopped the problem from occurring. I subsequently added about 3' to the overall length of the exhaust, and the problem went away completely.

I'm not sure exactly what was causing the problem, but it did go away, and everything appears to be fine. I also returned the mixture screw to its original position and everything still works fine.