TELEDYNE LARRS HELP

brian_25

CAN ANYBODY HELP ME I AM HAVING TROUBLE WITH A LARRS OUTDOOR HOT WATER BOILER

larry_9

What's the problem?

Paul B._2

Tech Support

Hi Brian,

What can we do to help?

The number for tech support is 800-900-9276x5406 from 6:00am to 4:00pm Pacific time.

I believe they can also be reached by e-mailing service@laars.com

If this is product application related e-mail me at pbock@laars.com or call me at 603-335-6300x562, and I'll see what I can do for you.

Paul B.

brian_25

THE MANUAL HIGH LIMIT KEEPS POPING I HAVE THE SET POINT AT 135 AND THE HIGH LIMIT SET AT 170 WHEN THE TEMP DROPS THE BURNER STARTS AND TEMP RISES QUICKLY FROM APROX 125 TO 190 AS THE TEMP CLIMBS BOILER STARTS TO VIBRATE . IF SET POINT IS SATISFIED BEFORE HIGH LIMIT POPS ALL IS OK . IF INLET TEMP IS 130 OUTLET SEEMS TO HIGH. CITY WATER, COULD HEAT EXCHANGER BE PARTIALLY PLUGED AND WATER NOT FLOWING FAST ENOUGH OR IS THAT UNLIKELY. I KONW THAT WATER IS FLOWING, FLOW SWITCH IS CLOSED AND THE 3 STORAGE TANKS WILL RISE TO SET POINT AFTER A RESET .I DO NOT KNOW HOW FAST THE WATER IS FLOWING.

Mark Eatherton1

Need a time delay relay...

Just guessing here, but if your pump shuts down upon satisfying the thermostat on the tank, the residual heat in the refractory is causing the outlet temps of the boiler to climb quickly, and causing the manual reset high limit to pop out. If you install a time delay relay on the extraction pump, it will allow the heat to but dissipated so it can't stack up and cause nuisance outages.

T/L makes a retofit kit for this application.

If you suspect partial blockage in the heat exchanger, you should be able to see that in the differential temperature across the HX. BIG delta T indicates low flow rate.

G'Luck!

ME

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Paul B._2

Mighty Therm or Pennant?

If this is a Mighty Therm Volume water heater the operating contol senses on the boiler inlet, and the High limit is on the outlet. We reccomend a 40° differance between the two controls.

There is more at work here than just that however,is this a new install or has it been in for a while?

does the unit have a factory pump, or is it field installed?

What model do you have, some of the larger ones will have a pretty low delta T if they have the correct flow.

Paul.

hr

Teledyne

should be able to supply you with acceptable delta T across that HX. Usually a gpm table is included in the installation manual.

If the house is a rocking, don't come a knocking. That noise is often common with a fouled HX. Test results will tell if you need to rod out the tubes. Doesn't take much build up to get them a howling

hot rod

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Paul B._2

All that information is on the website

The IOM literature and the sales brochures have some excellent engineering data. I usually update my referance material from the website as We update that before we go to the printer.

www.laars.com look in technical documents and submitttal information, the sales brochures have a lot of flow rate information.

Paul

brian_25

mighty therm, pump is field installed , unit is about 8 years old , dont have the model # with me . i bealeve it is 500k nat gas outdoor 2" inlet/ outlet, circ runs constant through 3 120 gallon storage tanks we replaced the motor on circ about 8 months ago 3/4 hp b&g bronze

Paul B._2

sounds like you need to

measure the temp accross the heat exchanger. If its been in for a while it might be time to clean the tubes.

Call me in the morning and I'll find some flow information for you. 603-335-6300x562, I'm in at 8:00 Eastern time.

Paul

brian_25

thanks for the help will call.

Mark Eatherton1

Sounds like...

whales in heat...

ME

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