Prestige Solo 60 on propane - ignition issues

Gordan

Well, more like: no ignition issues...



I had a guy come out this morning to do the combustion analysis and commission the boiler, and after a few hours, he left befuddled and frustrated. Basically, the boiler will ignite fine if he turns the gas throttle screw full on, but then the combustion numbers are all out of whack. Once he dials in the combustion within spec, the boiler maintains a steady flame while lit, but will no longer relight. There's really only that single adjustment. The LP pressure is about 12" WC, it dips just a little when the boiler is trying to fire. The electrode is sparking.



It seems like I find myself asking this question a lot, but - is there a trick to this that he's missing? He'll be getting in touch with TT tech support on Monday prior to coming back, but I wanted to cover all the bases.



Many thanks, and happy New Year!

tim smith

re tt 60 not firing

I would check spark gap, may be off a bit or refractory is touching it? Dial in #s while running then check spark gap. Good luck.

Gordan

What's the proper gap?

Couldn't find it in any of the docs. I measure about 1/4". The boiler is brand new...



Thanks again, Tim!

Gordan

Found it...

There was another version of the troubleshooting guide that had it. 3/16" gap, 5/16" clearance between electrodes.

Gordan

Gap's good.

So I guess this can be filed under the heading "gremlins."

Tim McElwain

Does any fault

code come up the controller?

Gordan

Just the ignition failure lockout, eventually.

The spark is good and strong. One interesting thing: I removed the test cap on the vent to make sure that the gas valve was opening, and wouldn't you know it - it lit. Then, on a hunch, I went outside and removed the "snorkel" on the vent termination - a long 90, a 3' length of straight vent, and then another long 90, just dry fit for the moment - and after that, it did light and went to full fire, and had a stable flame. This makes no sense to me, since I'm nowhere near the vent length limitation, which is 60 feet equivalent. My vent is: 8" straight, 45, 45 street, 45 street, 12' straight (and then the snorkel - 90 long, 3' straight, 90 long.) That last 90, one is not even supposed to count in the length. If the issue is not venting - and it really shouldn't be - then, does the fact that reducing the "backpressure" on the vent makes it light easier, suggest the likely culprit?



I want to emphasize that I'm just trying to narrow down the issue; I don't have the proper equipment to do combustion analysis. For that, the tech will have to come back out, but I'd like to make sure that next time he's successful.

Ross_7

Snorkel height

Hello,

According to the Solo Vent supplement, the maximum height of the snorkel should be 24", center to center with both 90 degree ells. Maybe you should reduce the height center to center & then see what the result is. Keep us posted, and good luck!

Ross_7

Correct you are

So how does your intake air terminate? Does it come straight out as shown in the diagram?  What is the difference between the Exaust & intake pipe? If you're exceeding the elevation as specified in the manual, then this may be part of the problem. It looks as though the 12"-24" differential is a constant. If snow isn't a problem try it with a 90 ell on the intake air as shown in the diagram, and use a shorter snorkel. If it doesn't work, then put it back the way it was. Keep us posted! I hope that you can get this resolved, because I think Triangle Tube boilers are outstanding. I have one in my own house & I love it!

Gordan

Actually...

It says that the vertical distance between the intake and the vent should be 12" min - 24" max, at least that's how I read it. Figure 4A in the vent supplement. Am I misreading it?

Chris S

ignition issue

I had a similar problem with a wm a few years ago.  Tech support blamed it on the btu output of the LP.  We increased the low end rpm on the blower by about 10% if I remember correctly and haven't had a problem since.  Not sure how that venting is being an issue.  TT is a great product, I'm sure they'll help you get through this 

Gordan

I think that the impact of the venting is a red herring.

If the ignition fan speed is fixed, then reducing the pressure drop against which the fan has to push would result in more airflow and more negative pressure at the venturi - just like increasing the ignition fan speed would. That snorkel amounts to almost half of my equivalent vent length, so removing it should have a significant impact on the venturi pressure. Something tells me that increasing the ignition fan speed will probably be what TT will suggest.



One more thing: the way we've had it running so far was with the front cover removed, which basically makes it cat IV, not direct vent - it was using indoor air. I'm a little nervous about what happens when I add even more pressure drop on the intake side...

Ross_7

Triangle Tube Tech Support

If your tech calls Triangle Tube, have him talk to Greg in Tech Support. Phone # (856) 228-8881. This gentleman has been very helpful in resolving the few & far between problems with any that we have installed.  We have a few on propane that  haven't had any problems at all. Let us know what you & your tech find out. Thanks!

mark schofield

intake air temp?

On a commercial natural gas Aerco modulating boiler in the school system I use to work for, we would have lockout problems during the colder winter months. After testing and troubleshooting visits from both the factory rep and the gas company, an internet contact told me about intermittent lockout problems when ramping up with cold intake air temps. Both exhaust and intake went directly thru long 12" pipe runs to the outside of the building. One day I disconnected the intake and fed the intake air to boiler with warm boiler room air. The lockouts stopped. The local fire marshal gave me the OK on a piping run to use intake air from the inside of the building. Alot of time and hours spent on a $20 repair.

Gordan

An embarrassing resolution

This is what insufficient sleep will do.



I had shoved crumpled-up paper into the vent and intake in order to keep the cold drafts from blowing into the house. I guess I hadn't taken all of it out before putting on the snorkel, because when I went out today to triple-check everything I found a big wad of crumpled up, wet paper in the snorkel - it had gotten blown in there. I am frankly amazed that the tech was able to get it to high-fire and low-fire stably (and cleanly) but it's no wonder at all that it wouldn't light.



Embarrassing, indeed. But just goes to show you: it's always the dumbest, simplest things that get you. With the intake and vent all connected as they should be, and the cover on, it is now lighting off and modulating reliably. Once the tech dials it back in I'm sure it will be bullet proof. One last question: the combustion analyzer was showing combustion efficiency at 91.6%. I would expect higher. But I guess that too would probably have been affected by the blocked vent? CO was also between 50-60 ppm on high fire.

Tim McElwain

I always tell

technicians that if they can't get a system to fire properly with the vent and air intake connected then disconnect the piping if it will fire then you will usually have a venting or air for combustion issue.



As to efficiency,  combustion efficiency is different than AFUE and will usually be below the AFUE numbers assigned to different units. They are actually two different things although somewhat related to one another in the overall actual efficiency



Figures suggested from TT for Propane are :



O2 2.7% - 4.7%



CO2 10.7% to 12%



CO 100 PPM



Electronic analyzers only actually measure directly by sensors the following:



O2



Stack Temperature



CO



The efficiency readings are a calculated reading using the electronic match of the other readings so don't get to concerned about numbers.

Alan (California Radiant) Forbes

Diagnostics

Doesn't TT have an error code for "Crumpled up paper in the vent or intake"?

Mark Eatherton

Yeah, it is

Code F- WTFO.... Manual interpretation reads "Loose nut behind the control pad.... Suggest replacement of the installer. 8-)





I was called onto a job (that I had lost to a lower bidder) due to a lack of flow through the heating system to one wing of the building. We ended up having to disassemble heating pipes and send a small sewer cable into the line and pulled a red mechanics rag out of the pipe where a 1-1/4 X 3/4 X 3/4 tee was located.



Seems that after they cut the old boiler out, to stop the pipe from dripping, someone stuffed a rag into the pipe, and someone else for got to pull it out before they connected the new boiler attempted to fill and purge the system. They'd used high pressure nitrogen, AND a high pressure commercial grade , truck mounted vacuum trying to get it resolved. All they really did was drive it further into the fitting...



Schmitt Happens :-)



Glad you got it resolved.



ME

Gordan

I guess I deserve that. :-)

Perhaps this thread should be moved to the bloopers section!



Thanks to all for all the help! Not only with this, but with my myriad previous queries.