Question About Corrosion Prevention.

[Stovedink]

I am new to hydronic heating. In April I purchased a house with two types of wood heat. A wood stove insert and a Rite Way wood boiler connected to a 1500 gallon heat storage tank for my in floor heat. The in floor heat is also tied to a propane hot water heater so you can either use propane or wood to heat the floors. In September I fired up the boiler for the first time after refilling my storage tank. Turns out the previous owners drained it and left it empty for about 7 years. The following day I walked into my garage where the boiler is and found the tank had a major leak. There was a good 2 inches of sludge left in the tank for those 7 years which ate holes into the bottom of the tank. I cut the bottom of the tank off, welded a new bottom on, refilled the tank, fired it up once more and now the system works great.

My question is this: Besides not emptying the tank and leaving it with sludge in the bottom to rust it out, what is best to add to the water to prevent corrosion of the steel and copper?

 

[maple1]

What kind of tank is it?

There are testing & treatments available. I forget who, hopefully someone will be along. Maybe something like 'precision chemical'. My supplier also had a spot on his shelf for bottles of treatment - the space was empty at the time so didn't find out anything about it. For starters you could maybe check a local supplier & ask, there's likely a recommened mix rate. But that's huge volume you've got there, it might cost big $ doing that.

If it's a closed pressureized system, I'd just seal it up & run it. As long as there are air vents to let air out when it needs to, the oxygen will deplete over time. But with the rough start yours had, I would definitely figure out some kind of treatment. But is this an open tank or closed?

 

[mustash29]

This place has some good reading, seems to supply some decent products as well.

(broken link removed)

 

[Stovedink]

Maple 1:

It is an open tank as far as I can tell. There is a pressure gauge/temp gauge on the boiler. The pressure never goes above 0. The tank is made of 10 gauge mild steel roughly 8 feet long, 8 feet tall and 3 1/2 feet wide. The top of the tank is removable. There is no gasket around this lid. There is also a fill hole on top that had a funnel with a plastic softball in it to keep dirt out I think. I left it as is.


Mustash 29:

Thanks, I'll check that out.

 

[Crizzoft]

Maple 1:

It is an open tank as far as I can tell. There is a pressure gauge/temp gauge on the boiler. The pressure never goes above 0. The tank is made of 10 gauge mild steel roughly 8 feet long, 8 feet tall and 3 1/2 feet wide. The top of the tank is removable. There is no gasket around this lid. There is also a fill hole on top that had a funnel with a plastic softball in it to keep dirt out I think. I left it as is.


Mustash 29:

Thanks, I'll check that out.

I had the same problem with my hydronic baseboard heating. (pressure gauge reading zero for the system). Mine needed to be at 20 psi to be working properly. I figured ill just open the water supply as it was closed by previous owner. Well that blew off the pressure relief valve and it wouldnt re-sit and leaked constantly. Replaced that and had my boiler serviced professionally. Turns out my pressure reducer was almost full open so it was adjusted and havent had a problem since.

 

[maple1]

I would definitely get some corrosion stuff in a big open steel tank like that - just a matter of time before it leaks again if left untreated.

 

[Sawyer]

I have the water for my Garn checked twice a year by Mike at PrecisionChem Lab. Initially I used a cleaner, followed by CLT-200, both supplied by Mike. I have been very satisfied with his service which is recommended by Garn.

PresicionChem Labs
W7231 State Hwy 49
Waupun, WI 53963

Mike Kuzulka
920-324-2007
Email [email protected]