Laars problem unit

Joannie_5

Hi, John.

Where are you? I'd like to get you in touch with the Territory Service Manager in your area, so we can help you figure this out. Let me know here, or email me directly jmishou-@-laars.com (just take those dashes around the @ out of the address). I'm in the office until 5:00 eastern today, and I'll be back in at 8:00 tomorrow morning.

Thanks,

Joannie

John Mills_5

HELP!

About 6 years ago, we put in a dozen Teledyne-Laars Mini Therm units. 100 & 125K with standing pilot. All but one have been just fine, this one is driving us crazy and has since day 1. All are similar installs, baseboard, some zoned, some not, various places in the house or garage.

The rollout manual reset likes to open. No pattern, sometimes goes months. It's mounted on the top of a burner box and temp analysis says it is doing what it is supposed to. We've even had a tech guy from the mfr rep out. Properly vented, spill switch has never opened, room off garage used to get very hot but large grille to attic above the boiler assures that no longer happens. Was about 40 in there today. Put a new switch in, opened shortly after. I watched the boiler heat up after resetting. Once outlet water got about 175, switched popped open. No rollout, no spilling, all just fine. 2 zones with valves, pump in the supply pumping away from the tank, 20-25 degree temp drop over the radiation.

Any ideas? Anybody used to this model? Anybody know someone at Laars I can call?

N. Pitz

Laars Minitherm

About 6-7 years ago, we installed quite a few of these. We have also had quite a few problems with them, and stopped installing them. I have had to replace the hot surface ignitors repeatedly, and two MiniCombos or whatever they were called (boiler mounted on top of 30 gal. indirect tank) were miswired from the factory. Spent a lot of hours staring at the wiring diagram and reverse engineering the boiler before I discovered the mistake. We also had problems with the rollout switches on a few. What we discovered is that heat builds up under the sheet metal cover, and trips the switch. Apparently at some point they started making covers that had louvers on top to let some of that heat escape. On one, we ended up having to leave the cover loose (not that I am recommending that) to keep it from tripping.

Good luck and hope this helps.

Steve Miller

roll out switch porbs

Sounds to me like the heat exchanger is clogged up. With the minitherms, its very important to pipe them in primary/secondary and have a means of boiler protection from cool return temps. If your return temps are over 20 degrees of the output temps, it cools the flue gases down and condensate forms in the vent connector and chimney and pours down into the heat exchangers. You need to removed the burners and take off the top cover and clean the coils of the exchanger. Then do something about the boiler piping to correct the problem.

Steve m.

Steve Miller

roll out switch porbs

> About 6-7 years ago, we installed quite a few of

> these. We have also had quite a few problems with

> them, and stopped installing them. I have had to

> replace the hot surface ignitors repeatedly, and

> two MiniCombos or whatever they were called

> (boiler mounted on top of 30 gal. indirect tank)

> were miswired from the factory. Spent a lot of

> hours staring at the wiring diagram and reverse

> engineering the boiler before I discovered the

> mistake. We also had problems with the rollout

> switches on a few. What we discovered is that

> heat builds up under the sheet metal cover, and

> trips the switch. Apparently at some point they

> started making covers that had louvers on top to

> let some of that heat escape. On one, we ended up

> having to leave the cover loose (not that I am

> recommending that) to keep it from

> tripping.

>

> Good luck and hope this helps.



Sounds to me like the heat exchanger is clogged up. With the minitherms, its very important to pipe them in primary/secondary and have a means of boiler protection from cool return temps. If your return temps are over 20 degrees of the output temps, it cools the flue gases down and condensate forms in the vent connector and chimney and pours down into the heat exchangers. You need to removed the burners and take off the top cover and clean the coils of the exchanger. Then do something about the boiler piping to correct the problem.

Steve m.

Steve Miller

roll out switch porbs

> About 6-7 years ago, we installed quite a few of

> these. We have also had quite a few problems with

> them, and stopped installing them. I have had to

> replace the hot surface ignitors repeatedly, and

> two MiniCombos or whatever they were called

> (boiler mounted on top of 30 gal. indirect tank)

> were miswired from the factory. Spent a lot of

> hours staring at the wiring diagram and reverse

> engineering the boiler before I discovered the

> mistake. We also had problems with the rollout

> switches on a few. What we discovered is that

> heat builds up under the sheet metal cover, and

> trips the switch. Apparently at some point they

> started making covers that had louvers on top to

> let some of that heat escape. On one, we ended up

> having to leave the cover loose (not that I am

> recommending that) to keep it from

> tripping.

>

> Good luck and hope this helps.



Sounds to me like the heat exchanger is clogged up. With the minitherms, its very important to pipe them in primary/secondary and have a means of boiler protection from cool return temps. If your return temps are over 20 degrees of the output temps, it cools the flue gases down and condensate forms in the vent connector and chimney and pours down into the heat exchangers. You need to removed the burners and take off the top cover and clean the coils of the exchanger. Then do something about the boiler piping to correct the problem.

Steve m.

John Mills_5

THANKS!!!

For Brian's fast call. We came to the same conclusion that Steve did, clean the heat exchanger fins. This thing is in a laundry room and there is lint building up on the bottom of the fins.

Rodney Summers

Teledyne-Laars Mini Therm unit knocking

After adding a new zone panel and zones/ new expansion tank - boiler developed wicked knocking... has to be air but can't get it out.. This is about a 15yr old unit JVS160 - any suggestion who I can contact at Laars?
Thanks
Thom Smyth
New Hope PA
tsmyth@comcast.net

Joannie_11

MiniTherm

Hi there.

I got your email this morning and emailed you the guy to contact. Let me know if need anything else.

Joannie

KCA_2

Knocking?


Hi There....

Knocking usually comes from a lack of flow.

What is the DT of the Supply & Return?

:-) Kca

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Jerry_15

Ditto, on every count - I have had some luck stuffing a strand of boiler rope across that opening, and I have seen some folks replace the roll-out with an auto-reset adjustable, but the bottom line is, well, you know.

Jerry_15

There you go. It may stop the knocking, but... Check the pressure with a real test gauge. Might be surprised.
PS Have you checked the gas manifold pressure? These boilers will kill you if the flame ain't right on. Condensation in the fire box, drooling off the vent stack, clogged heat exchanger, all sounds painfully familiar. Check and set up the others while you're at it and save yourself another call. Better yet, charge them for a clean and service on all the boilers, they're way overdue, and set up a yearly maintenance contract.