Munchie nuisance lockout problem

steve p

Try HTproducts tech support 800-323-9651 they seem very helpful.
goodluck

John McArthur_2

Nuisance LO on 199M

I have a 199M that has a couple of nuisance lockouts. It is an LP install (done by someone else)that has F10, F9, and Pro lockouts during the night.

The LP inlet was a bit on the high end 13.5" WC, CO2 is 9.9 with CO about 140 at high fire. The water pressure is a steady 15psi at the tridicator but the pressure switch still opens. The system has been purged of air and has a spirovent on the heating loop. Even with the pressure switch bypassed it still faults to F10 and occasionally F9 during the night. The unit will run fine all day, even with me inducing cycling by varying loads from the slab. The unit is piped P/S per the manual with a Grundfos 26-99 on the boiler loop pumping into the boiler. The control is set to 150* max temp and does not have an indirect hooked to it, only radiant floor staple up.

Any ideas? This has been occuring since startup.

Al Corelli

Check for wetness on the board connectors or at the sensors.
The only time I've had that happen, is when there was glycol in the boiler and it leaked (seeped, glycol "always" seeps) onto the sensors and wreaked havoc.

I changed the afflicted sensors and sealed them up well, no trouble since.

Electronics will act weird when wet.

Couderay

munchkin

Mine does go on F09 lockout quite a bit too, since new does restart on its own after an hour though seems to take more than 3 times hence the lockout. Took boiler apart cleaned the interior and checked spark electrode flushed out exchanger as per instucted and problem is not as noticeable now.Also cleaned flame rectification probe. Mine is propane too. But get in touch with HTP and see what they have to say as they have been upfront and straight forward with me. Good Luck.

John McArthur_2

I have heard HTP tech support is really good. The system has water only and I have not noticed any leaks. Seems a bit funny that it does this with a new startup. I have installed and started many mod/cons without any problems. Hope it is a simple fix.

I plan to call HTP from the job on Friday so I can give them real time readings and make on site adjustments.

Thanks all for the replies. I did a search but did not find much.

hr

Is the vent pitched back to the boiler prop[erly so it does not

> I have heard HTP tech support is really good.

> The system has water only and I have not noticed

> any leaks. Seems a bit funny that it does this

> with a new startup. I have installed and started

> many mod/cons without any problems. Hope it is a

> simple fix.

>

> I plan to call HTP from the job on

> Friday so I can give them real time readings and

> make on site adjustments.

>

> Thanks all for the

> replies. I did a search but did not find much.





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hr

Is the

vent pipe pitched to drain back to the boiler, properly.

The condensate drain working with the pin hole pointed up?

The unit itself level so the condensate doesn't trap in the combustion chamber. Some have to be shimmed to drain properly.

hot rod

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John McArthur_2

The vent runs vertically right from the back of the unit. I'll check the unit level and pinhole details. Good points that had not occurred to me.

Leo G_99

speaking of vents...

had one where the vent was not terminated properly. Actually had rain water returning to the boiler through the cumbustion air vent.

Leo G

Guy_6

condensate

I would suspect re-circ of exhaust. Before you jump and say that it is vented per instruction, consider this: Sometimes, due to enviornmental conditions, even correct will not work, well, correctly. Is there a prevailing wind during the day that would move exhaust gas away from the intake, or one at night blowing toward it?
Can you put a TEMPORARY extension on either pipe to get the exhaust even further from the intake, and give it a few nights trial run?
Whenever possible, try to terminate the exhaust ABOVE the intake: that warm plume doesn't like to go down.

Another thing that I had run into was the flat plate terminations with cross bars flat on the face. When the boiler would modulate down to it's lowest point, the exhaust gas would lull around the vent and be drawn back in. The fix was to cut out the grid from the termination.

Guy_6

read again

You stated that the vent runs vertical from the unit. Does it TERMINATE vertically? Is it a concentric termination? Those have an occasional habit of being piped backwards, exhausting from beneath the head. Don't be offended- I piped a shower backward (Hot on the left, correct? Not from the back side. It is in a summer home, and is now a great laugh for weekend guests. Well, for US anyway.)
Put your analyzer on the INTAKE air and run the unit through it's paces. You should only see clean, fresh air.
No CO or CO2.

John McArthur_2

Good points guys. I didn't install or vent the unit but I certainly will check the vent termination. Tech support suggested a drop in gas pressure as the culprit. I don't see how that could be it since it is an LP install and currently the only appliance in use. It is supplied by 1" black iron about 10' TDL from the second stage regulator.

I'm going to the job tomorrow and will check the suggested items. It is supposed to be -21* tonight, hope the HO doesn't freeze! According to the HO the problem seems to be getting more frequent.

I greatly appreciate all the well thought out replies. Thanks again.

tim smith

F10 LOCKOUTS

We just worked on one with this problem, Looked at combustion, ok, looked at vent, ok. Was told to clean the bolts and nuts and facing they touch on the burner cone to keep a good ground for flame signal, also clean the wire connection for the flame rod on both ends, F10 lockout stopped, go figure. Tim

John McArthur_2

Was that on a new boiler? I'll definitely try it, a poor ground makes sense. Hate to have such a bad experience with the first Munchie I did the startup on.

tim smith

F10

No it was on a 2 yr old boiler. I did not know that this was a new startup. Being new, make sure the ground is to a good grounding source also. Gl, Tim

John McArthur_2

I'll also check the electrician's ground. I am anal about grounding all of my control work, boxes, pumps, etc.

A bad ground seems to be a logical cause of the issue.

Leo G_99

Tim,

got the same advice about 1.5 years ago. Since then i always clean the mentioned items on every annual.

Good pick-up!

Leo G