Laars- Mini Therm & Superstor-Ultra water heater

mazz

Hello-
My wife & I purchased a 2,700 sq ft home in Colorado recently which has radiant heating supplied by this Laars-Mini Therm natural gas & also is used to heat the water heater as well. This home was built in 2007 . The Laars system has been working fine thru the years from previous owners & also these past 5 months for us , however it does make a loud humming sound when it turns on & stays in while heating . We’ve considered replacing it with a new efficient system & was wondering what recommendations you would advise & if it would be cost effective ?? Or should we just keep the Laars - mini Therm until it is no longer efficient ? Would greatly appreciate your advice & help .
Regards,
Bob 

mazz

Zman

What you have is an inexpensive medium-efficiency boiler that will probably last 20 years or so.
I new condensing boiler would provide new features like outdoor reset and would probably increase your net efficiency by 10-20% depending on the type of radiant you have. If you are burning natural gas, there probably is no ROI if you replace it.

Can you post a video of the noise? It doesn't sound like a tough fix.

Alan (California Radiant) Forbes

I work on a lot of Laars boilers and while not the most efficient, they have proven themselves to be reliable in the long haul. Whatever money you save with a modern, condensing boiler will very soon disappear with one or two service calls, let alone the frustration of being cold and having no hot water in the middle of Winter, waiting for the service company to show up.

The heat exchanger will sometimes soot up, especially with a low temperature radiant system like yours so I would have it checked every couple of years and make sure it's not clogged; cleaned if necessary. You have to partially disassemble the boiler and wash down the copper heat exchanger elements; a very messy job, but it will restore the boiler.

The humming sound from these is common. It's usually from the transformer and I usually move it around with my fingers to make it stop. Call Laars at (800)900-9276 to get a more professional solution.

I don't see any means of getting fresh, combustion air into that room. Are there any vents in the walls or ceiling?

I would find someone in your area that is used to working on these boilers, not someone that comes in and says you should get rid of it for a modern, condensing boiler "that will save you all sorts of money".

EBEBRATT-Ed

@mazz, by all means keep it running. That boiler is still made today. And that means something when the new mod cons last 10-15 years if your lucky and IF you can get parts for them they are big $$$$

mazz

Appreciate the comment & reply !👍

mazz

Thanks Alan, appreciate the advice & I will definitely look into cleaning the heat exchanger & suspect it hasn’t been maintained from previous owners , the humming sound is annoying also & is kinda loud turning on & while it’s running . 

mazz

Thanks for the reply also Zman , I’ll send a video & sound of the noise , humming sound going on & running ! 👍

hot_rod

A humming sound can also be caused by scaling inside the boiler. There are cleaner chemicals that can help 
with copper fin tube boilers both the inside and outside of the finned HX need cleaning

HomerJSmith

Be sure an wear at least a N-95 mask if you clean the copper fin tubes, I made the mistake of not doing that once to my dismay. You can't live without your lungs. Experience is a polite name for mistakes!

mazz

Thanks so much for the advice Hotrod & HomerJsmith , really appreciate it . What brand & kind of cleaner do you recommend for cleaning the copper fins ? ? Is there any videos on cleaning & servicing this model Laars Mini therm JVH  ? 

hot_rod

I like the Rhomar products. These aerosol cans are handy, screw onto a boiler drain and pull the trigger. I'll bet you can find a You Tube showing how to clean the coils on the outside. It's a messy job. Wear protection, as suggested.

Alan (California Radiant) Forbes

I still don't see any vents for combustions air. It's kind of important.

mazz

Alan, not sure what you mean by vents ? There is a main aluminum vent that runs outside from the main boiler above outside patio……takes excess fumes from boiler to outside ……

mazz

Alan (California Radiant) Forbes

Yes, that's your exhaust flue. There should also be vents that bring in combustion air from outside. Do you see any vents in the ceiling or in any of the walls?

mazz

No, no vents at all, it’s a small mechanical room right next to the garage door …..I’ve seen a few mechanical rooms with boilers & never seen one with the vents your talking about though ? ? 

Alan (California Radiant) Forbes

Newer, condensing boilers usually have a pipe specifically for fresh combustion air. Atmospheric boilers like yours require vents to the outside to bring in outside air.

Here is what your boiler manual says about combustion air for your boiler:



And I'd make sure you have a carbon monoxide alarm in or just outside your boiler room.

mazz

Hey Alan, really appreciate the info & advice. We just purchased this home 4-5 months ago & had it inspected before we bought , obviously the inspector has overlooked this issue…..we do have a carbon monoxide alarm installed right outside the door & hallway , I just installed one last month. Would you happen to have a picture of these type of vents installed in a mechanical room so I can get a better idea on how they are installed ? Thanks so much again . Bob 👍

Alan (California Radiant) Forbes

There are many ways to get this done depending on the location of the mechanical room. If there is an outside wall, a couple of properly sized vents in the wall may be all you need. If you have to bring air down from the roof, there may be some ductwork involved because you need venting high and low. If it's difficult to bring in outside air, there are guidelines for using indoor air for combustion. The rules vary depending on the codes used in your area. And obviously, the tighter, more insulated houses need special attention.

An inadequate air supply can cause all kinds of problems. Carbon monoxide production from inadequate combustion, sooting boilers, odors in the house, control lockouts.................