Lochinvar Solution boiler issue with high temp/relief valve/tank

boof1975

I have a 10 year old Lochinvar Solution boiler. I mostly use wood during the cold cold months, but in season transition I use the boiler for my hot water and heat. Sometime last year it started rumbling and making whistling noises. I started to observe and noticed it occurred when it was at high temperature 200+. So I had the local Lochinvar "experts" come out four different times and never fix the problem. They tore it down, cleaned it, called the Lochinvar experts in Indiana, but never fixed the problem.

Here is what I've found in my own diagnosis. The setpoint temp is 140, differential at 11, and high fire at 10. The aquastat on the outlet is currently set at 200. I can't get any air OR water from the expansion tank. The relief valve spits water EVERY time it heats up. I'm currently only heating water.

I just fired it up to start working on it again and with the setpoint at 140 it will continue to heat until it gets to approximately 215 and then shut down. Still no water or air from tank at any time during heat up. Relief valve trickles water the whole time from approximately 150 +.

Any ideas would be appreciated. I know it's getting too hot. But I also think the expansion tank has issues.

hot_rod

It sounds like you don't have enough, maybe any, flow thru the boiler. Popping, banging, percolation, moaning are all sounds that indicate lack of flow. Also that it races to 200F when fired.

Check the pump size and operation, you may need to remove it to see if it spins when powered.
Assure it has good air elimination, it could be air locked.

What is the pressure on the boiler?

How did they clean the boiler? Was a descaler chemical circulated thru the boiler?

Relief valve seep could indicate a waterlogged tank, does it feel heavy when you try to wiggle it, or feel full when you rap your knuckles against it?

boof1975

The circulation pump seems to be working fine. I'm not sure how to test that but the lines running the particular zone I used for testing heated nicely.

The pressure on the boiler was about 20PSI.

For cleaning They didn't do any descaler chemical in the boiler. They took it apart and cleaned used brushes to clean the inside of the unit. There was some minor build up on the "fins" and they claimed this could cause issues. No change.

The tank feels light and airy. When wiggled it feels empty - like the bladder is stuck shut.

I do have hard water and I'm wondering if this is clogging stuff up? Maybe tank is jammed up and maybe needs some of the desclaler you are talking about? I'm wiling to replace tank just because but I know that's probably not the key issue. And the high temp has me concerned but I'm not sure that's not normal.

hot_rod

So the pressure must go to 30 psi to cause the relief to drip? Maybe the gauge is not accurate?

If the pressure goes from 20 to 30 the tank may be undersized, improperly pressurized, or failed. Is this a new problem or has the relief always trickled when it fires?

Often when temperature rises quickly or overshoots in that boiler there is a flow problem. And the noise it makes also would point to flow issues, caused by partially blocked heat exchange tubes.

Any leaks in the system causing fresh water to enter? That will scale them up quickly.

boof1975

The relief drips prior to 15 psi if I remember correctly. It started almost right away after heating started. I'd have to double check as I was trying to watch everything and record what I found.

This is a new problem. I've only owned house for 4 years but didn't have any trouble until last year. Relief valve only started trickling recently - the noises started well before that.

No leaks that I know of.

hot_rod

You could have a few things going on. Needs a new relief if it drips at 15 psi. But something caused it to go off and eventually fail, often excessive pressure over and over.

Check tank pre-charge
When running check in and out temperature, that along with kettling sound could indicate time to delime.

The manual may explain the procedure to descale the boiler. You can download one if you do not have the original.

DZoro

What air elimination device do you have? Is it above your air tank? Remove the tank then look up into the piping from the tank to the system and confirm no plugging issues. Your air elimination device maybe scaled up to the point that the system doesn't "see" your tank. Pictures would help
D

boof1975

I haven't removed the tank to look yet but here is what the system looks like near the boiler.

hot_rod

Maybe step back a get a wider view.

There is another circulator in the system? I think the pump in the pic is dedicated to the boiler flow, not intended to be the system pump?

Is the manual nearby, see if the piping matches the requirements shown in the manual.

boof1975

I don't see that specific "system circulator" pump on my system. Just the one by the boiler and then the individual zones.

boof1975

Also looking for descaling or deliming instructions but do not find any in my documentation or online. Is there a standard way to go through this process? I think that might be a good place to start. That and replace relief valve and maybe bladder tank?

DZoro

change the tank and air vent, make sure those pipe ports are clear and free of any rust/debris.

hot_rod

From what I can see, when the boiler is piped that method, "full flow" you need to assure a that any of the pumps can provide adequate flow as per the boiler requirements.
Read below: system flow cannot be lower that required boiler flow.

Also a pump, providing adequate flow, must run whenever the boiler is firing.

If a thermostat turns off the pumps while the boiler is still firing, not so good.

With that many pumps you should not need a boiler probably 500W of pump heat in the room.

Zman

I am thinking you have several problems occurring at the same time:
The expansion and and or relief valve need to be looked at.

The boiler control seems to have some issues. 140 is probably too low for a non condensing boiler. 200 is way too high, especially when set to 140.

Those copper tube boilers have very low mass and very low surface area to BTU ratios. They do not do well in low flow situations. That snap, crackle and pop is likely little micro flashes of water, boiling, expanding and collapsing in the boiler exchanger. Does the problem get better if you turn on all the zones? I would recommend repiping boiler per manufactures instructions.

hot_rod

looks like someone added a strap on thermostat at the boiler? If that is set at 140 it may be intended for boiler return temperature protection?

Zman

I had assumed this is baseboard heat. Is that correct?