I was wondering if any one is having water/steam hammering in their wood boiler and how to get rid of it. The hammering starts right at peak fire, when it is going good. I have my wood boiler in parallel with my Burnham oil boiler. From day one I have had this problem. I don't know how many times I hooked up a circulating pump to try and purge all the air out. I have three air separator's on it. One 1 1/4 located on my highest point, a coin vent located on top of my wood boiler, and one coin vent located on my oil boiler. I have tried a higher pressure (15-18 PSI) and still have the hammering. Right now I have a Taco 007 pump mounted to the wood boiler. I also was told to try and get more circulation. Would a Grundfos UPS-1542F give me more circulation that my Taco? This problem is driving me crazy. The wood boiler is located right next to my oil boiler. Any advise would be appreciated. Thanks Doug
Steam hammering in my Solo 40
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Try replacing the coin vent on top of the wood boiler with an automatic air vent. That's what finally worked for me.
I had the same problem with my Scandtec Solo 30 last year. I ended up resolving it by purging air from the coin vent on the top of the boiler. It hasn't happened since then.
I kept venting until I gave in and got the taco auto vent. I haven't had a problem since. Put in a 3/8" ball valve before the auto vent, that way if the vent goes bad it can be replaced easily.
Great idea Chuck with the ball valve. I thought about putting in the auto vent, but didn't think of the shutoff.
My understanding is, not that hammering should occur at all, that hot spots produce some flash steam, which again condenses back to water. Possible a little steam collecting at the top of the boiler during the intense burn, but that as the boiler cools a little it disappears by condensation. I don't see any problem with the autovent, but not sure that it really is needed. Maybe others have different thoughts.
depending where the water outlet is it could be that air is being trapped in the top of the boiler. make sure the boiler is level or SLIGHTY tilted so air can move to the outlet. If you get air or water trapped it can flash boil and cause this.
leaddog
leaddog
Thanks for the ideas. I talked with a Tarm guy yesterday and he thinks my 1 1/4 auto vent maybe in the wrong place. I have it on my suction side of the pump and it maybe sucking in air. He recommend draining 10 or 15 gallons and try to purge air again. I will change my auto vent next summer. Thanks again.
Well I drained 10 or so gallons, refilled, and purged my boiler. I fired up the boiler and so far I have not had any knocking or hammering. I need to re-do my anti-air location next summer. Thanks Doug
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