LAARS EBP-175 noise. Please help.

nikolay23

Hello,
I have LAARS EBP-175 heating/hotwater unit with 3 heating zones. There is a boiling-bubbling noise coming out of the boiler chamber when the heat is on for any of the 3 zones. As the result all my radiators (not cast iron, but those slim aluminum radiators) are very loud with water constantly pulsating back and forth very loudly. I had the plumbing company bleed all the zones, but it is still the same. They are out of ideas right now. It does seem to me that the boiler chamber is not making this noise when there is a request for hot water and it is working on hot water request. It is appears to be happening when heat is on only. Cannot sleep normally at night because of this noise.
Any thoughts and suggestions are greatly appreciated.
Thank you,

SuperTech

Is your circulator pump functioning? Is your aquastat over heating the boiler? What does the gauge read?

newagedawn

ear plugs, sleeping pills, or competent technician, ask another company

Tom_133

The anti condensate could be stuck or bad. I dont believe that would effect the hot water production ( I could be wrong its been awhile) That is if your unit is old enough to have the device, its the honeywell zone valve on the right hand side in the unit. If thats not fully opening or even just a little then the boiler will percolate and make noise.

serviceman

Nikolay23
Please contact me at LAARS so we can help resolve your problem
603-335-6300 ext559

nicholas bonham-carter

Thanks Serviceman, that’s the sign of a responsible company, caring about the customer.—NBC

Erin Holohan Haskell

nicholas bonham-carter said:

Thanks Serviceman, that’s the sign of a responsible company, caring about the customer.—NBC

Yes!

nikolay23

Thank you Serviceman. Will call you on Thursday.

nikolay23

Circulator pump seems to be functioning, but not sure how to tell for sure. I was kind of suspecting the same. It is the original Grandfus pump. The gauge reads 20psi (I know it is a little higher than it should be for some reason). The boiler doesn't seem to be overheating. Boiling chamber noise start right away before even the boiler ignites as soon as it starts showing "BFE -flow temperature" (when i assume some command comes in from the board). Then it continues when the igniter fires up at 166 and temperature starts going up.

SuperTech

Keep us informed of the outcome.

nikolay23

I do have that honeywell zone valve on the right. Not sure how to tell if it is mulfunctioning.

nicholas bonham-carter

Is this house and system new to you, and therefore this is a longstanding problem?
Maybe if the pump is in the wrong place in the system, the pressure reduces when it is pumping, causing the heated water to flash to steam. If so some repiping may be needed in order to rectify the problem.—NBC

Tom_133

You should see the arm on the zone valve open when the boiler hits temp. Its a bit of a tough one to diagnose. Did you call tech support yet?

nikolay23

It is not new. It's been there for 13 years. Started happening this winter

nikolay23

Quick update: Spoke with the gentleman from LAARS (serviceman) earlier today and he was very very helpful. He has made arrangements for someone locally to me to come out tomorrow and take a look

nikolay23

Update: Plumbing company specializing on LAARS boilers stopped by on Friday. 2 junior guys.... They did basic checking, bled all 3 zones again, spoke with LAARS technical support verifying few things such as Grandfus pump. Nothing was found and I am still back to where we started. I was told by their boss that there is nothing wrong with the unit or any of the internal components and it is related to the piping system itself. The only things outside the unit are few pex pipes, pressure valve, brand new taco 007 pump, brand new expansion tank, 3 electrical zone switches and few copper pipes for actually zones). The next course of action that was proposed is to completely flush the whole system/boiler doing boiler treatment at the same time. Rough estimate I was given was around 900-1K to do that and no guarantee. Not sure what to do at this point as no one seems to be able to find the root cause of the problem.
Any further advice/help s really appreciated.

lchmb

has anyone tested your water and PH level's? Also does this start on the call for a heat cycle, mid cycle or end? Is it constant with just one zone or all. You said it started this year...what if anything changed? was it serviced and then started? Where are you located? And last...can you post some pics? all the zones and and venting.. all around the boiler... It almost sounds like it's in the anti condensing valve or something related to temp. If you leave it running on domestic water for 20 minutes does it start to make noise? If not and you shut HW off and turn on heat does it start immediately?

Tom_133

Post some pics, of the outside piping. I am still not convinced its not the anti condensing valve. If you have hot water and it doesn't make any noise, then it makes noise when it switches to heat, then that valve comes into play when the water temp is hot enough it will open. If it doesn't open, or if internally it doesn't open enough I can see it making some noises.

Its odd that LAARS support couldn't make it work?

Where are you located?

nikolay23

Thank you very much LCHMB & Tom for your input. I attached some photos. Let me know if this is what you were looking for.
Below are the answers to your questions

PH was never tested
Noise starts as soon as there is a call for heat, before the boiler even ignites
It is happening to all 3 zones
Nothing recently changed between last winter and this winter (i just installed 2 nest thermostats)
I am located in New York City
Just tested running water when thermostats were off. There is some minor boiling noise as well, but not as much as when heat is run and not as loud (running hot water -occasional single boiling noise form the chamber)
When I turned the water off and put the heat on, noise started right away and much louder and I can hear both boiling noise as well as water running/pulsating noise from the boiler and copper pipes right outside the boiler.
Unfortunately working with LAARS we hit the deadlock and they couldn't find anything. Both plumbing company and myself spoke with technical support.

nikolay23

Just listened to the boiler again few minutes after my daughter started taking the shower and didn't really notice any boiling noises at all.

Tom_133

The noise happens on any of the heating zones not just one? You also said the black pump on top of the boiler is new? This for sure is odd.

nikolay23

Correct. It happens with all 3 zones. That pump (Taco 007) was replaced back in the beginning of February by the plumbing company as they suspected it to be the problem. Do you think this could that anti-condensing valve as you had previously mentioned. What does this valve do in this specific unit?

GBart

I had something like this happen years ago with a Slant Fin boiler, it sounded like the percussion section for Santana in the chimney, we tried everything, what we finally found was a funky casting in the back section that trapped air and when the burner was on it started dancing and boiling whatever water was with it, very faint at the boiler but loud upstairs.........had to replace the block.

Not saying this is what's happening here but it sounds similar.

GBart

Cases like this usually require a factory trained technician who can review the installation and if they end up stumped then they call in the factory rep, which is what we did in that case above.

nikolay23

In my case it is loud at the boiler. I would suspect chimney problem would also affect domestic hot water as well. Right?
I already had plumbing company specializing in LAARS (actually sent by LAARS) look at the unit and they didn't find anything even being on the phone with 2 techs from LAARs. I am thinking it might the anti-condensing valve that was mentioned by 2 people earlier. I am waiting for their feedback.

GBart

The manual for your unit states the following:
"Boiling (kettling) may occur at boiler discharge
temperatures from 170°F to 210°F. The temperature
at which it starts will vary from one installation to
another. The primary cause of the problem is poor
heat transfer on the inside of the boiler coil. This may
be caused by foaming due to excessive concentration
of antifreeze in the system or by scaling from the
boiler water due to hardness of make up water.
Plumbing antifreezes should never be used in a
boiler system. Only boiler antifreezes, with effective
antifoamants, are appropriate for the ENDURANCE
boilers. Note: The concentration of appropriate antifreeze
should be always be kept as low as possible to
minimize its effect on heat transfer and efficiency.
The method for eliminating the boiling noise is
the same regardless of the cause. However, if
antifreeze in the system is suspected of being the
cause, the concentration (<35%) and type should be
investigated."

Boiling(kettling) may occur for other reasons as well, it could be a minor flaw in the heat ex, these types of systems have very little water, if they list boiling in the installation manual they know about it, it could also be some sort of weird flow issue.

It's page 33
https://www.laars.com/images/uploads/products/1117F.pdf

nikolay23

I spoke with the company that installed it and there is no antifreeze there ( i guess it wasn't used in this system). LAARS teach was also asking me about this. LAARS tech ruled out heat exchanger already

GBart

If the sound is coming from that area I'm not sure how they could rule it out. Also you stated it only happens in heat not hot water.

It can take time, odd sounds have happened in almost all brands and sometimes it is only one or a few units out of the entire production line, when the cause is found please post it and good luck.

lchmb

I would be curious to know about the hardness of your water to see if it's something building in the HX. I suspect your issue lies in the anti condensing unit. I would also take a clamp style temp sensor on your outlet and see what it is raising to...could be your boiling. I had a similar issue in my cast boiler and added a bottle of 8 way.. stopped the problem over night...

nikolay23

Thank you very much for your input.
So you think it might be worth trying to target the anti-condensing valve as the next step? I was reading that it has a cartridge inside that can be replaced instead of replacing the whole thing. What do you think? Is this something I can do myself or I need to get a plumber? Is there any easy way to test it?
(https://forum.heatinghelp.com/discussion/102372/changing-anti-condensing-valve-on-laars-endurance)
Also could please tell me what this valve does in few words in this unit?
I am sorry, but I am not really sure what you are saying below.. Could you please clarify?
" I would also take a clamp style temp sensor on your outlet and see what it is raising to...could be your boiling. I had a similar issue in my cast boiler and added a bottle of 8 way.. stopped the problem over night.."

the_donut

> @nikolay23 said:
> I spoke with the company that installed it and there is no antifreeze there ( i guess it wasn't used in this system). LAARS teach was also asking me about this. LAARS tech ruled out heat exchanger already

> @lchmb said:
> I would be curious to know about the hardness of your water to see if it's something building in the HX. I suspect your issue lies in the anti condensing unit. I would also take a clamp style temp sensor on your outlet and see what it is raising to...could be your boiling. I had a similar issue in my cast boiler and added a bottle of 8 way.. stopped the problem over night...

You should take a sample of water and boil it on the stove to check for foaming. Also check ph, total dissolved solids and chlorine content.

If it foams, treat water or fill with good quality water.

nikolay23

Could this also be the plate heat exchanger (that rectangular box) that sits next to the flow switch. Maybe it is clogged and need cleaning?

GBart

nikolay23 said:

Could this also be the plate heat exchanger (that rectangular box) that sits next to the flow switch. Maybe it is clogged and need cleaning?

But if the factory and tech were there/on phone, didn't they cover these questions?

nikolay23

They did, but i am kind of hesitating right now as to what i had observed and told them. I am seeing mixed symptoms on different days. One day domestic hot water doesn't make any noises in the boiler, other days I might hear something, but not much. Unfortunately, the company LAARS sent out to check the unit did very little troubleshooting basically just bleeding zones and checking grandfus pump. They didn't check anything else.

GBart

a ha

city water or well?

the reason I ask is city water is usually balanced, well water is whatever, one possibility is mineral deposits not allowing good heat transfer, I would think they would have flushed parts of the system, heat ex to check for flow and muck

nikolay23

I have city water. They didn't check any of the part or valves besides grandfus pump just to make sure it was opeartional

lchmb

From the best I can follow, the boiler is not piped correctly. It's a bit hard to follow with the pictures but it looks like the circulator is connected directly to the boiler. They generally want that boiler piped primary/secondary.

nikolay23

I am not sure about piping the boiler, but it's been working fine like that for the last 12 years. My next door neighbor has his boiler piped exactly the same. I haven't had a chance to troubleshoot this any further and trying to get in touch with LAARS again to see if they can help me any further with troubleshooting.
I have spent some time over the weekend trying to listen to the boiler under different scenarios.
It does look like that the boiling noise also happens when there is an initial call for domestic hot water before the boiler actually starts. It doesn't happen as much compared to call for heat. But once the boiler starts after there is a call for hot water i don't really hear any boiling noises during this time. Any thoughts on this please?
Basically I have boiling noise any time when there is a call for heat that starts right away even before the boiler starts. I have minor/occasional boiling noise when there is a call for hot water before the boiler starts, but it seems to disappear when the boiler starts for hot water.

nicholas bonham-carter

By “before the boiler starts”, do you mean: before the flame ignites? I presume the pump will start first, as well as the combustion air fan. Either of these mechanical things could be ready for retirement after 12 years, or there could be a bubble of air moving into a high spot in the piping, impeding the flow.
The rogue air bubble might explain why it does not always happen with regularity.—NBC

nikolay23

Correct. Before boiler starts I mean the grandfus pump starts working and heat/ hot water is available. The boiler then ignites as soon as the temp goes down to about 164-166F.

nikolay23

My biggest problem is a very loud water pulsating noise in all 3 zones (baseboards) which I suspect is the result of this boiling noise from the boiler itself. It appears to do something to the water before it runs through all 3 zones. I have no idea what do to and no one seems to be able to figure this one out. I am trying to reach out to LAARS but no luck so far.