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Master Plumber
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Discussion Starter #1
We have a boiler at work to produce hot water for a one bay carwash,and it also runs the floor heat.

Up until last Dec we had 2 separate systems( hot water heaters) to do this. They became defective due to age.

We had a guy come in and told us a boiler will do both jobs at once with the help of a heat exchanger.

After they hooked it up when the boiler shut off it would pop and bang rather loudly(like it was gonna blow up)

We called them back and the service guy says we need an expansion tank( which the guys doing the install said we didn't,they had it with them)

expansion tank was installed and worked good for awhile

Mid summer the popping and banging started up again. The service guy said there was calcium build-up in heat exchanger and circlation pump

Again it worked fine for awhile

He came back again last week and said we need a new pump and heat exchanger as it is probably full of calcium

Today we got brave and took the pump apart to see if it was calcium.(he has not come back yet to install new stuff)

No calcium, but a lot of pressure in the expansion tank(obviously)

We are wondering if the expansion tank is in the wrong spot ie. working against the re-circulating pump? It is teed in after the pump and just before the heat exchanger.We feel the water in the exchanger can not release because the constant flow going to the exchanger is working against it

They deny that it is a problem and blame it on a lack of a softner.

Interesting enough, after we released the pressure today, it is working fine for now again.(probably until the expansion tank fills up and the water in it has no place to go)

Sorry for the lenghty dialoge, but it gives you a bit of history to go on

Thanks

------

I am gonna take some pictures of the set-up as well
Hoo boy!
 

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Always Something
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1,369 Posts
Sounds like the Xpansion tank is not set to the correct pressure. If pressure is dynamic, than a regulator is needed, and tank is pressurized to same amount...maybe a pound over. The popping and farting is typically calcium carbonate solidifying in the tank, not a danger but in a boiler?....I dunno about that.
 

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Master Plumber
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1,069 Posts
Discussion Starter #3
Sounds like the Xpansion tank is not set to the correct pressure. If pressure is dynamic, than a regulator is needed, and tank is pressurized to same amount...maybe a pound over. The popping and farting is typically calcium carbonate solidifying in the tank, not a danger but in a boiler?....I dunno about that.
Without pictures I am farting in the wind.

I just thought y'all would get a kick out of the email.
 

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I agree it is like farting in the wind without pics... but first off the exp. tank would be in the wrong spot if it is upstream of the circulator. they should move it to the low pressure side(downstream). if it is a low mass non-condensing boiler, they might not have a primary loop which would cause boiler shock and banging. Not sure just guesses lol
 

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Master Plumber
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Discussion Starter #5
I agree it is like farting in the wind without pics... but first off the exp. tank would be in the wrong spot if it is upstream of the circulator. they should move it to the low pressure side(downstream).
Of course. But I'm not even about to mention taht until I see pics. Because then they would probably go just move the X tank and then blame me when it still didn't work.

I am trying to decide how much I want to be involved in this one.

My kid brother did tell another guy to kiss off this week. Wanted him to design & install his heating system. Up north, 10K sq.' building with 16' ceilings. He had an old, used, 100K Burnham his plumber told him is plenty to heat the building. Radiant heat.

Building is up. Ready for boiler piping. But he's not going to insulate it until next summer. It's a metal building. His plumber (and I use that word loosely here) told him it won't heat real well until it's insulated but it should heat it up to around 50 degrees without insulation.

He believes the idiot. But he wants my kid brother to design & install the boiler piping.

You know how this one would end up. It won't heat at all, use tons of gas, and my brother will be blamed.

I do think he got him talked out of using CPVC for the boiler piping. But other than that he told him there was no way he could be involved with a nightmare like that. Told him to go get his sorry plumber to do it.
 

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yeah, I figured you probably knew but thought i'd say it anyways. I doubt a 100K boiler will heat that building, I would be very surprised if it did! but then again I don't know what area it is designed for. I hate when customers try to get us to install old used equipment like garborators, or HWT's or anything else like that.
 
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