Repair or Replace Gas Boiler

bigjohnnymack

Hi , my 30 year old teledayn lars

FHW natural gas

boiler blew up the t & p valve , copper tubing it was soldered on right off the boiler .

Prior to that , the second floor baseboard lost its heat.

First floor baseboard was still giving off heat. Boiler operating and heating.

Running like that for 4 weeks.

When one evening a loud explosion occurred in the basement.

Upon checking, I found the boiler not running and a little water around the boiler.

Looking further, I saw that the T & P valve had blown right off the boiler top.

Is the boiler repairable ?

By repiping a new T & P valve to the boiler and flushing and purging the air out of the first and second floors baseboards.

Then restart the boiler and do a boiler check.

( What causes the second floor baseboard to lose its heat ? )

Air in the system ?

Water filled evaporator tank ?

Clogged water feed valve ?

Thanks

John M.

pecmsg

Repair or Replace Gas Boiler

bigjohnnymack

Mar 6, 2025

Hi , my 30 year old teledayn lars

FHW natural gas

boiler blew up the t & p valve , copper tubing it was soldered on right off the boiler .

Prior to that , the second floor baseboard lost its heat.

First floor baseboard was still giving off heat. Boiler operating and heating.

Running like that for 4 weeks.

When one evening a loud explosion occurred in the basement.

Upon checking, I found the boiler not running and a little water around the boiler.

Looking further, I saw that the T & P valve had blown right off the boiler top.

Is the boiler repairable ?

By repiping a new T & P valve to the boiler and flushing and purging the air out of the first and second floors baseboards.

Then restart the boiler and do a boiler check.

( What causes the second floor baseboard to lose its heat ? )

Air in the system ?

Water filled evaporator tank ?

Clogged water feed valve ?

Thanks

John M.

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View Post

Are you\ saying the threads where the TP relief screws into the boiler stripped and the entire valve shot out?

EBEBRATT-Ed

Sounds like either you don't have a low water cutoff or the LWCO did not work.

The boiler should be inspected for damage. If it looks like it may be ok it needs to be disconnected from the system and a hydro test done to check the heat exchanger.

Thats for starters

Jamie Hall

It may or may not be salvageable — I wouldn't say repairable. I wouldn't bother; too much more or less difficult to detect damage may have been done by the overpressure event.

In fact, I would scrap it, the expansion tank, and any trim, such as the defective pressure relief valve, the low water cutoff (if there even was one), aquastat controls — the lot. Again, not worth the time and effort to find out which redundant safeties failed.

Then start all over again.

Mad Dog_2

You got a long run out of that Tlyne-Laars...That's not even a company any longer, but Laars make a really nice replacement. Mad Dog

mattmia2

Could be the expansion tank was waterlogged and the relief valve was scaled shut. Could be system was low on water because the pressure reducing valve failed and it had a leak of some sort and the boiler got low enough on water that the boiler heated the joint on the relief valve to the point where it melted the solder because part of it was dry firing. In either case it would be best to replace the boiler after either event.

Did water pour out of the relief valve piping?

bigjohnnymack

pecmsg

Mar 6, 2025

https://forum.heatinghelp.com/discussion/200854/repair-or-replace-gas-boiler

Are you\ saying the threads where the TP relief screws into the boiler stripped and the entire valve shot out?

* Thank you

Yeah The T & P valve and valve pipe it was affixed to shot right out of the top of the boiler . . Exploded boom.

bigjohnnymack

EBEBRATT-Ed

Mar 6, 2025

Sounds like either you don't have a low water cutoff or the LWCO did not work.

The boiler should be inspected for damage. If it looks like it may be ok it needs to be disconnected from the system and a hydro test done to check the heat exchanger.

Thats for starters

* Thank you

bigjohnnymack

https://forum.heatinghelp.com/discussion/comment/1847012#Comment_1847012

* Thank you

I tend to agree .

Get a replacement gas boiler.

Any suggestions on brand gas boiler.

Thanks

bigjohnnymack

https://forum.heatinghelp.com/discussion/comment/1847044#Comment_1847044

* Thank you

That Tele Larrs boiler was a good boiler. 30 + years old.

It was used in heating swimming pools.

Thanks

bigjohnnymack

Thank you

Sounds about right on.

Probably scale clogged the

Valves And T & P.

Low Water - then hot steam -

Boom - T & P Valves and valve pipe shot out - exploded.

Looking For Replacement Gas boiler. Burnham , Weil McClain , Crown , Utica . .

Thanks

mattmia2

I assume it uses a HX to heat the pool water?

EBEBRATT-Ed

You should probably stick with the same type boiler if it worked. Larrs or RayPac also make them

Mad Dog_2

Laars makes a great product & fantastic tech support & warranties. Mad Dog