No Heat Thermostat Question

adayton_2

> Check power to the board then power from the <BR>
> board to the igniter. check for good <BR>
> grounds.<BR>
> <BR>
> If all else is running must be one of <BR>
> the two. <BR>
<BR>

Brad White_11

No Heat Thermostat Question

Firstly, Merry Christmas Everyone! And what the heck are you doing surfing the Wall?? (Good to get away, yes I know...)

Open and possibly dumb question. My Susan has the oversized 160 MBH Burnham Series 2 circa 1991. A few weeks ago she awoke to a cold house, so she calls her local heating expert (yours truly).

After a few checks of the obvious things (power, thermostat settings, high limit, etc.) I twisted the wires together and lo, we had heat. And heat was good. I replaced the thermostat with a spare Lux 5-2 programmable I had kicking around. All was good. A few days later, same thing, cold house. I reinstalled the Lux after doing the wiring twist again. All worked fine.

I finished this with a replacement with a more suitable Honeywell Smart Resonse 7-day about two weeks ago. It immediately took like a duck to water and we had a warm house at 5:30 for example. Fast learing curve, that.

This AM, no heat. I have not gone over yet, but wondering why something so reliable could be so, well, unreliable... So far she has boosted it up and down, shut down the red plate switch (equivealent of control-alt-delete) with no results.

I will do the wiring twist again and will re-install as this has worked in the past. But frankly this does not give confidence.

I am heading over there soon but any ideas? Has to be something simple...

Thanks!

Brad

Rodney Summers

breakout the volt meter

I'd start check'n transformers, is the 24V stable? Grounds OK?

will smith_4

no heat

Could be cycling off on limit since it's oversized. Check to see if there is a flue damper-the proving switch is a service call waiting to happen. Is the pump cycling?

Brad White_12

voltages

Thanks. I did check (just got here moments ago). Transformer is putting out 24V plus or minus one volt. It is not the T-Stat. something in the igniter path I think. Circulator is running. vent damper cycles open but no spark igition. Grounds are clear (full potential across L-G and L-N. Any thoughts?

Brad White_12

Yes.

Per other post, all but the ignition is working. Boiler is cold. Do not see a manual re-set high limit. Operating HL is set at 180, BTW.

All power checks out. Relay pulls in, pump is on, damper open...Seems to be ignition failure.

We are fortunate in that today and tomorrow here in Boston ww should have daytime temps in the 50's. Thankfully a gas heater is in the playroom!
Any other thoughts?

brucewo1b

I had this happen recently, customer put on new t-stat and could get no heat in one zone, I go over do the twist test all is fine, replace t-stat no go, In the process of pulling it off the wall I hear click click, so I pulled a new stat wire and all was fine, when I pulled out the old one there was a staple had gone through one of the wires, in one position it would work, but back on the wall and the wire moved enough to break contact, yet it had run fine thirty some years with the staple however the wire had never moved until the new t-stst.

Bruce

Mitch_6

No heat.

Check power to the board then power from the board to the igniter. check for good grounds.

If all else is running must be one of the two.

adayton_2

Deja Vu, :-), no heat but thermostat

> Check power to the board then power from the

> board to the igniter. check for good

> grounds.

>

> If all else is running must be one of

> the two.

superMARKet

Damper

Damper opens, no ignition?

Does your damper motor/control have LEDs on it for troubleshooting? If the ignition light isn't coming on, the damper isn't opening fully or the switch doesn't realize the damper is open. If the damper can't be trusted, try putting it into "service" mode and opening it fully with a screwdriver. You might be able to make the switch make contact even if the motor can't. If this works, leave it alone with the damper bypassed temporarily until you can get a new motor on there.

adayton_2

Deja Vu, :-), no heat but thermostat

replaced. Does this burner have a optical flame safety detector or a stack relay?? lol. I just went nuts for a week of so with heat cutting out inexplicably to find out it was the stack relay. It was not totally tripping out on safety (which would then have to be manually reset)but merely interrupting the heat cycle. Just a painfull) thought.....Alfred

Brad White_12

Stack Relay

Not that I can tell. This unit is 1991 or so, no board nor LED's. We called a service company given that I know my limitations. Will keep you posted on the outcome!

Thank you all!

Brad

Brad White_12

Damper

Damper is open but no LED's. I will try what you suggest but also not leave it there

I may advance the diagnosis for when the service co. gets here Tuesday AM (God Bless 'em)...

Peace to all!

Brad

Unknown

Brad

I'll put my money on a problem with the thermostat wire somewhere between the boiler and the thermostat. If you disconnect the thermostat from the boiler relay and it fires every time, this certainly sounds like the case. I've seen it before and I'll probably see it again.

Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

Brad White_12

Glenn- Hi

Long time. Not the thermostat nor wire. Both at the transformer and at the 'stat, crossing the wires closes the relay. Damper opens, pump runs. No fire in the whole, unless I am missing something. Still open to suggestions though. You are the man when it comes to Burnham-

Thanks for checking in!

Brad

Unknown

Brad

From your first post it appeared to be a thermostat wire problem, but after reading your subsequent posts I know understand better. Follow the voltage from the vent damper switch to the ignition module. If you set your meter to the 24v AC range and check each device after the vent damper you should find the problem. Check the voltage between "C" on the transformer/relay and each side of the Flame Rollout Switch, each side of the Blocked Vent Switch and then to the Ignition Module. If you are getting voltage to the Ignition Module are you getting a spark? There is a very helpful Troubleshooting Flow Chart for the boiler ignition system in the back of the I&O manual.



Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

[Deleted User]

I'm placing my money...

on either a bad damper end switch or a bad ignition module.

Chances of having that many bad themrostats is slim to none.

Try physicaly grabbing the damper motor blade and giving it a twist. If it works, put the damper switch into the MANUAL postion until you can get a replacement.

ME

Weezbo

I'm thinking We Know the T stats good....

So the easiest thing is to keep the thermostats pull the boiler out and put in a MPO *~/:)

that way you can lose the Nat Gas and make the fuel oil companies happy.

Brad White_11

Thanks, Mark

In fact the T-Stats were the culprit initially but as we are collectively finding it is in the ignition train. I think we are on to it. Whatever it may be, the tech who shows up tomorrow will have an advantage thanks to you all. Temperature outside now is in the high 40's so some grace...

Susan moved the family Chanukah dinner to her sister-in-laws house, so there IS a silver lining!

Still I will check out what you and Glenn have postulated and let you know-
Thanks again and enjoy Boxing Day!

Ralph DiTore

some expert.... LOL

Ralph DiTore

some expert.... LOL

so she calls her local heating expert (yours truly).

[Deleted User]

Hey Ralph..

He said she called HER expert, not THE expert. At least Brad had the common sense to know when to say WHEN. I admire that in a a man.

ME

[Deleted User]

As an aside...

we've been having a WHOLE bunch of premature failures of the aquastat relay packages that this and everyone elses boiler uses. It has a double pole relay, one which fires the pump, and the other that fires the boiler. THey begin having intermittent problems, easily fixed by "touching" the boiler (I HATE when that happens..) and eventually failing completely like yours has done.

Good luck and let us know what the tech finds. I LOVE trouble shooting from my PC:-)

Wish your honey a Happy Channuka.

ME

rob

Heating Sudoku......

My day off and I'll play troubleshoot 101.
Circ running, no ignition. Heat call. 24V at w on relay
W-C. 24V to damper. C- schematic point. 24V to ICM
Possible scenario: intermittent damper fault, end switch or relay. intermittent ICM fault Check ua at FSR.
Flame sense lock-out Check resistance to ground at burner
Check compatibility of Tstat- check w to ground
A VOM will be needed to perform any of the above.

Brad White_11

Funny, Ralph....

Actually I am an HVAC engineer so more on the design side, less so on hands on (and I am no slacker there either). I did diagnose the problem but also am willing to admit when it is beyond what I want to mess with in the physical sense... But I take your ribbing all in good cheer!

Brad White_11

Thanks for the validation Mark-

My dad had the best definition of "expert":

From the Latin "Ex", meaning "a has-been" and
"Spurt", meaning "at drip under pressure".

And next time, I told Susan she would get faster response if she nudged her expert instead of calling...

Thanks for the Channukah wishes, Susan was beaming when she read that..

Happy New Year, ME!

Brad

Brad White_11

Thanks, Rob-

I will pass that on to the tech. Having me there tomorrow may rack up more time for him but I will do my best to leave him alone, while learning at a respectful distance. As stated, I am a good engineer, but distinctly amateur technician. I learn more from techs than anywhere else...

Weezbo

Theres the wisdom in the word.

Good man Brad. Even though it sounds like a problem in the module testing it is the ticket ,without the tools to do so one can only make an educated guess by observation.thats the tru thats your word.that thou art *~/:)

Brad White_12

Found the Problem, Mark...

It was the yellow wire.... harness connection was loose, probably for years. Once snapped in it would not release by itself. Luck of the draw. The tech discovered it because his meter also is a jumper (my Greenlee is just an RMS meter). Common knowledge to you but the best $136 I ever spent (for the service call). I am a better person for it now...

Thanks for all your help and all you do...

Let the dinner begin...

Later!

Brad

CJRS

happens even to the best of the best

many stories I am sure can be told by the experts feeling like a buttt-head some days. About a year ago I expressed my concdern over a newly installed radiator only to find that the I didnt see a papar towel inside the pipe when the pipe fitter cut the pipe for me. Removed the blockage and WOW it worked....cant say I wasnt embarrased on that one since it took three days to figure out only by diconnecting the piping. Learned my lesson to check all pipes in the future.