First Munchkin failure

Wayco Wayne

My 2nd munchkin install has been running since mid december. Got a call this morning that it had failed but the homeowner had re-set it himself. It then ran all day and failed again tonight. I'm going down to check it tomorrow. He says it tries 3 times and fails on F09. For those of you who have experience to share, what should I look for first. Thanks in advance. (The local distributor is giving a class on Munchkins in the Spring. Great timing) WW

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paul lessard_3

check page 10

my firerite is full of condensate is this bad?
good luck paul...

Wayco Wayne

Paul

I don't understand your answer. Could you be more specific?
Do you mean I should adjust the gas to air ratio? How do I do that? The instructions in the book give the combustion settings but give no procedure that I can find.
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[Deleted User]

Munchkin problems

I hate to say this but I had one do the same thing.It would run for some time then, problems with the pressure switch. I replaced this switch 3 times with new ones from the factory and it still was a problem. I finally got a new munckin and it has never been a problem since. I asked the rep. what was up with the one I took out and they have never gotten back to me.

munchkin-man

Munchkin F09 code info

If the CO is to high the flame rectifiction probe can get a coating on it that you may see as a white powdery substance or you may not be able to see any deposits at all. Simply be sure you are in high fire and meter your CO level. If you are above 100 PPM addjust the gas valve cw using the throttle addjustment screw shown on page ten of the installation manual. This will decrease the btu rate in to the combustion process thus bringing down the CO PPM level. This should eliminate the F09 code on a frequent basis.

Wayco Wayne

Update on Munchkin problem.

Talked with the local Munchkin rep techie. (I call him munchkin Bob. If when I meet him he's diminutive in stature, I will surely be arrested by the PC police) He asked where the job was located and he predicted when I told him I would find a low inlet gas problem. He said the munchkin needs 7 inches inlet pressure even when the system fires up. I installed a meter on the drip leg. I had 7 inches until it fired up and then promptly dropped to 5.5 inches. I went outside and turned up the regulator so it would maintain 7 inches and I haven't heard from the customer yet. (2 days and counting) WW

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Unknown

Wayne - does the gas co

permit service personnel to adjust the pounds to inches regulator in your area? Just curious???

Also if you had a static pressure of 7" and fired the unit and it went to 5.5" inlet at the unit I would think that is an undersized outlet piping problem. What was the pressure after you screwed down on the house regulator? Are there other gas appliances on this system? If so they may have excess pressure now which could cause CO problems. When you screw down on that regulator it affects the entire house.

Unknown

Munchkin 7\" min pressure???

better not put any in the inner city of most areas of New England. We have areas that have a hard time maintaining 5" to 6" pressure in the mains with peak demand. I will have to talk to Munchkin folks about that one.

Wayco Wayne_2

Tim

I've never heard of it being a problem. At least one time in the past I have neen in contact with the gas company concerning low pressure and they instructed me to adjust it myself. That was 8 years ago. If there have been any changes I have'nt heard of them. WW

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Unknown

Typically most gas co

do not want anyone but themselves to adjust pressure.

Up here in New England it is a code vilolation. Any problems with regulated pressure has to involve the utility.

I will have to look into that min pressure requirement on Munchkin that really presents a big problem if correct. We had a similar problem with Hydropulse boilers that they required a minimum inlet pressure. We would not allow them to be installed on our low pressure systems.

Scott22

A couple of years ago, we had a similar problem with a couple of Voyager heaters. In that case we were given medium pressure gas by our utility provider and we regulated the pressure down as it entered the various buildings on site. Even with tweaking of the regulators we couldn't get the pressure just right, ie: not too low (<7") and not too high (>9"). It turned out that 2 of our regulators (they both looked exactly alike) had been switched during installation. We had the wrong orifice on the wrong line. Once this was corrected, all was well, except for the ignitors, but that's a story you've heard before.

Larry_7

Reg adjustment

The Gas Co. here forbids reg adjustment at the meter by others because the meter index is compensated to measure the gas at a given pressure. If the pressure is increased or decreased, measurement is no longer accurate. If 7"WC is available at the oulet of the meter and press drops too much at the inlet of the equipment, the piping is undersized.

The Munchkin folks appear serious about adequate supply to the boiler. After examining their instructions (after our proposal was accepted), we realized they want the piping sized for a maximum .3" drop as opposed to the usual .5". On our first install, the existing piping was borderline undersized per their specs and we wound up enlarging the piping to cover that concern. This cut our profit on that one but now the existing piping will be scrutinized more closely before the bid.

If your press at the meter was correct to begin with, the drop at the boiler is just a symptom of undersized piping. Although cranking it up outside may compensate for the piping losses, accurate measurement is lost.

The gas supply requirements are slightly confusing for the Munchkin. As an example, the way I read it, they want a min of 7" available while unit is on standby or in operation. If 7" max is available at the outlet of the meter, piping would have to be sized for zero press drop in order to have 7" at the unit while firing. We sized by the .3" table in their manual and haven't had a problem.

Larry

Unknown

Here in RI

the utility sets the high pressure pounds to inches regulators for 6" pressure out of the regulator and all the meter indexing is set up for those pressures. That will definitely present a problem in this area with the Munchkin.

Bill Barrett

Munchkin

Wayne please let us know what you find, I’m very interested.

Glenn Harrison

6\" standard in Chicago Suburbs too.

Normal inlet pressure residential is 6" to 6.5" and gas company won't normally service reg's until pressure drops below 5". If a Munchkin requires 7" while running, then every house that one was put in would probably have to be converted to high pressure with stepdown regs at each appliance (like that's going to happen).

Jeff Cook Munchkin man, what say you about the 7" inlet presure claim.

Mark Hunt

I've got


several running with 6.5" and not one problem.

Mark H

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ChrisL

N. Suburbs working fine

I never measured inlet pressure, but my install in the northern suburbs of Chicago has been running fine for over a year now.

Chris L

Wayco Wayne

It failed

twice in 2 days before I made the adjustment. It had been running trouble free since middle of Dec. It's been 4 days since I made the adjustment and no call from the customer. (knock wood). Makes me wonder what the problem really was or is. I need to learn more.

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Glenn Harrison

Well, I decided to look into it myself and...

according to the manual at the htproducts website, on page 10, and I quote "The gas pressure must remain between 7" and 14" during stand-by (static)mode and while inoperating (dynamic mode)."

If you want to see, go to

http://www.htproducts.com/literature/lp-61.pdf

and scroll down to page 10 (you will need Adobe Acrobat reader to view it).

Unknown

I had read that

in my notes. I have a feeling that it might not be so critical to be an exact 7". I think it was written in the sense that they anticipate that as normal natural gas pressures. Most gas valves will operate okay down to 5" inlet pressure. They use a european Honeywell valve V8115 I believe is the number. I am not sure what the minimum inlet pressure for that valve is. I will be in touch with Jeff Cook tomorrow and will find out.

Glenn Harrison

I'll be very interested in a final answer on this,

because as you said and I know normal natural gas service is 6". I wonder though because since this is a differential pressure valve, it's hard to say. I have seen this valve in the Lennox CompleteHeat systems and I know they are real sensitive to steady incoming pressure, although Lennox calls for 4" steady inlet. Maybe it is a C.Y.A. measure on HTP's part.

Ben_3

Gas pressure

I have measured hundreds of homes incoming gas pressures for many different reasons related to strange heating problems. I always found that you will see as low as 5" steady and up to 7" steady. If munchkin thinks everybody who buys this boiler will be able to maintain a steady pressure they have never dealt with a utility co serviceman in the Chicago area. I have had my digital manometer in hand showing a drop or low pressure and had them still tell me there was no problem or better yet they would ask if that was a problem. I used to service many Hydropulse boilers in the area, I stress "used to", those kind of problems cause homeowners to run when they hear the name and contractors to cringe. Almost always ends with the product being replaced with something not quite so touchy and usually less efficient but at least it works.

Colin

Munchkin Gas preasure fix

> I have measured hundreds of homes incoming gas

> pressures for many different reasons related to

> strange heating problems. I always found that you

> will see as low as 5" steady and up to 7" steady.

> If munchkin thinks everybody who buys this boiler

> will be able to maintain a steady pressure they

> have never dealt with a utility co serviceman in

> the Chicago area. I have had my digital

> manometer in hand showing a drop or low pressure

> and had them still tell me there was no problem

> or better yet they would ask if that was a

> problem. I used to service many Hydropulse

> boilers in the area, I stress "used to", those

> kind of problems cause homeowners to run when

> they hear the name and contractors to cringe.

> Almost always ends with the product being

> replaced with something not quite so touchy and

> usually less efficient but at least it works.

Colin

Munchkin Gas preasure fix

Gentelmen: We have found the easy fix seems to be oversizing the dripleg.
Instead of using a standard 3/4" nipple supersize it,1 1/4" x 8" seems to take care of the problem up to 140M, but we have used 2" x 20" for a 339,000 instalation.

Colin

john wood

Big Drips!

Yeah; I've had some contractors do something similar to fix an intermittant problem with munchkins. I think what happens is on marginal size piping or marginal regulators that there is a "resonance" set up between the outside and inside regulators that causes problems. Best is to use the reccommended pipe sizing and always have at least 3/4" to the boiler.

Unknown

John, explain \"resonance\"

on regulators. I am not sure what you are talking about. I would also think that any heating system should be installed with piping and regulators well outside the marginal barriers. I am a believer that all gas heating should have a minimum 1" piping system directly to the boiler or furnace. Did this for years at the gas company and never had any problems with pressure to the equipment.

As soon as I left they dropped that rule and went to sizing according to the charts.

Mark Hunt

MAN!!


You're strict!!!

I do not run 1" all the way to the equipment, but to within 10'.

For the Munchies we run 3/4" as per manufacturer's directions.

As I said, I have never had a problem.

Mark H

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munchkin-man

pressure drop from 7\" to 5.5

tells me you have an undersized gas line (not enough volume to supply to the BTU rate requirement)pressure is fine the gas valve should not see more that a .5" drop under normal conditions. The Munchkin is in many areas were we have seen as low as 3.5" in the dynamic mode,and still runs fine because there is suficiant volume. All the gas companies I have ever delt with will not let you touch the meter/regulator. I would not go there if I were you. The statment on installing a accumulator/resivor on the drip leg at the unit in many cases will over come pressure drop I have seen it done in many applications on many peices of equipment were the piping is undersized and they can not repipe due to existing in wall piping with finished living area. We state the 7" simply because it is a normal range in most locations. The gas to air ratio should never be addusted. It is factory addjusted by Honeywell. Remenber the longer the venting the less make up air you will get. The speed limit in our nation has been established for a reason. Like the speed limit being exceeded most of our instructions on limitations are exceeded.

Earthfire

piping

Tim , just did an addon vent free heater in a commercial building that was originally piped by moonlighting gas company employees about 10 yrs. ago. It had 5 125,000 btu ceiling hung unit heaters. The front of the building had 2 connected and that had a run of 125 ft.of 1in. pipe. The back of the building had 3 units on 110 ft. of 1in. pipe. they had used 3/4in. to connect the units to the 2 mains in the basement which were fed by 1in. from the meter.The customer had just bought the building, and thought the addon would be a simple tap and mount. Life is never simple and you don't know who to trust.

Unknown

They probably got all the pipe from

left over jobs they did on company time. The truth is they should no better.

Glenn Harrison

So what your saying is,

it's not neccessarilly the incoming pressure itself that can cause a problem (to a point) but it is a drop in gas pressure on startup that can cause problems? Would these units be better off with a secondary inlet regulator at the unit? I ask because Lennox is using this same valve in their Complete Heat units which have a similar burner setup, and they recomend using a 5" inlet regulator to eliminate rough ignition problems due to inlet pressure drops.

Mark Hunt

I think what he is saying is


do you're homework. I was in a home the other day that had a problem with a gas fireplace insert. The problem was that whenever the furnace came on the flame in the fireplace went out. I looked things over and found that the gas line feeding the whole home was 1/2", and the connected load was 200K!

Now is that a problem with the insert, or is it a problem with the guy that ran the gas line?

There are SO many things we have to look for when we sell a job. Look now or pay later!

JMHO!

Mark H

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Glenn Harrison

I agree with you there, Mark.

Just thinking out loud and taking into consideration that this is not an ideal world. I'm also just throwing an idea out there based on another maufacturers experience with these Honeywell differential pressure valves. In a replacement stituation it may occasionally be impossible or cost prohibitive to replace the gas line to meet a .3" drop spec, so therefore maybe an alternative should be available, such as Lennox came up with. I agree though that proper size piping is the way to go, but everyone might not do it.

Mark Hunt

Excellent point Glenn


Here is how we differentiate ourselves from the rest of the pack. We do our homework.

NEVER compete! DIFFERENTIATE!!! SEPERATE!!!

Is this a cool business or what?!?!?!?!??!?!

Mark H

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Glenn Harrison

You've gotta love this job

I wouldn't have stayed in it for the past 12 years, and be looking forward to at least the next twelve if I didn't!

As far as doing homework, that's why I'm askig questions. Can't get the answers if we don't ask. And in the long run I'll be the best damn tech I can be.

Mark Hunt

AMEN! (nm)



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Wayco Wayne

Munchkin failed again

After 5 days from raising the pressure we had another failure. I was told by Munhkin bob, the local techie for Munchkins that Washington D.C. is having problems all over town because of bad pressure drops in the morning due to the crappy piping under the streets, and everybody turning their heat on in the morning at the same time. Says Baltimore is having no problems because their piping is newer. Wash DC piping was apparently installed way back when dinosaurs ruled the earth. He had me turn an ajustment screw to increase the "chamber pressure" I've not been trained on this boiler yet so I just do what he says. I'm considering doing the resevoir trick on the vertical gas piping to try and stop the nuisance calls. The couple that own the house have been very nice and I want to keep it that way

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Unknown

What kind of regulator

are you talking about??? Is this regulator put before the gas valve? Does the valve have a regulator built in to the valve or is the valve set up to run on line pressure?

I was always warned to not put two regulators in series as they would work against one another????

munchkin-man

Correct it is not always incoming pressure Glen

Look at it this way you have a fire in your back yard 5' from the your house you have a 5' hose with water at house pressure. You turn the water on and put out the fire. The next day you have a fire 200' from your house. Using the 200' of hose under the same pressure you try to put out the fire but the water is not coming out fast enough. Why? A contracror installed an 80M Munchkin in a home the gas pipe was 3/4' existing and was 90' long at 7" this gave him 110,000 available BTU'S of gas. The net rating on the 80M is 74,000. He fires up the munckin and presto less than .5" drop and the unit runs fine. The next contractor installs a 199M with a net out put off 183,000 BTU'S the gas pipe is existing and he has 90'at a pressure of 7". He fires up the Munchkin and bummer it has a 4" pressure drop and will not run with in the specifications set forth. The flame rectification probe feels an absents of micro amps and says hey no flame close valve. Why?
NOT ENOUGH VOLUME. The pipe inside diameter is not large enough. Now most of you know this in your heads you just needed to have it brought to your attention. Take the same hose at 5' and start to pinch it off still have same pressure but the volume of water coming out the hose starts to fall off. My point the issue we satrted with in the beginning of this sring still exist. Any questions?

Unknown

Yes I have some questions

I have received several private e-mails about this post on Munchkin. They have been asking me some questions which ironically are the same questions I have so here goes:

1. What adjustments should be made in the field to the gas valve on the Munchkin?

2. How do you adjust to get below 100 ppm on CO?

3. What should the perimeters on outlet pressure be? On high fire? On low fire? And in between as it modulates?

4. How do I know if the Munchkin is at full input - high fire when I am making the adjustments, is it not modulating? By the time I clock the burner it may cut back on temperature???

5. What is the actual minimum inlet pressure at which it will safely fire? What are the specs on the gas Valve?

6. Do the instructions give specific procedures for adjustments?

7. One of the posts stated " to adjust the throttle to 100 ppm using the throttle, which will bring DOWN the btu rate on the problem boiler". But if the gas supply pressure was low at that job, wouldn't the air/fuel ratio have been too lean to begin with?

8. Last of all I am a little confused with the factory answers:

a. adjust the gas valve to bring down the input, that will solve the problem.

b. Never touch the gas valve it is set by Honeywell

c. you have to have the adequate gas supply pressure to be sure the input is not reduced

I am confused which of these is the correct answer.

And finally what is this problem about the blower and is there a factory bulletin out to everyone on it?

Bill Barrett_2

Ditto to Timmie's questions!!!