# Banging on new hot water baseboard system



## plumbthis (Sep 12, 2013)

I have a customer ( an apartment complex ) who had major upgrades done , and one of the buildings is making a loud banging noise when the heat is on . I have checked everything possible and I'm down to the boiler being installed backwards ( supply and return crossed in the boiler room ) it is a mono-flow system with Danfoss non electric zone valves , can this be a logical cause ? I'm not familiar with these valves and we are getting ready to reverse the lines next week , figured I would put this out there to see what the cyber- plumbing world has to say , thanks btw , first post , I'm brandy spanking new here


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## rjbphd (Feb 5, 2010)

plumbthis said:


> I have a customer ( an apartment complex ) who had major upgrades done , and one of the buildings is making a loud banging noise when the heat is on . I have checked everything possible and I'm down to the boiler being installed backwards ( supply and return crossed in the boiler room ) it is a mono-flow system with Danfoss non electric zone valves , can this be a logical cause ? I'm not familiar with these valves and we are getting ready to reverse the lines next week , figured I would put this out there to see what the cyber- plumbing world has to say , thanks btw , first post , I'm brandy spanking new here


I know, I know!! Sorry can't help ya.... post a proper intro..


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## plbgbiz (Aug 27, 2010)

PZ is a site for those already in the plumbing trade. You are welcome to view the site and use the information available to you. Please refrain from posting until you have established that you are active in the trade. 

Start here>>> http://www.plumbingzone.com/f3/ 


Thanks.


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## plumbthis (Sep 12, 2013)

plumbthis said:


> I have a customer ( an apartment complex ) who had major upgrades done , and one of the buildings is making a loud banging noise when the heat is on . I have checked everything possible and I'm down to the boiler being installed backwards ( supply and return crossed in the boiler room ) it is a mono-flow system with Danfoss non electric zone valves , can this be a logical cause ? I'm not familiar with these valves and we are getting ready to reverse the lines next week , figured I would put this out there to see what the cyber- plumbing world has to say , thanks btw , first post , I'm brandy spanking new here


 Good morning , I posted this a few days ago without following the rules since that day I have corrected the error of my ways , I apologize for this bad start ! ( I guess I don't read directions very well ) anyway does anyone have any Ideas , the system is a hydrotherm kn-4 with taco 1 hp circulator pumps and danfoss non electric zone valves , there are 12 buildings and this one banging is the smallest like I said I checked the obvious , is it possible the pumps are to oversized ? I'm going today to check each unit to determine if all 12 zone valves are installed in the right direction , thanks any ideas would be appreciated


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## rjbphd (Feb 5, 2010)

I'll be nice for once... what size, btu boiler is this, what size pipe,coming out, going in?? Pump on supply or return?? Got any pictures??


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## wyrickmech (Mar 16, 2013)

plumbthis said:


> Good morning , I posted this a few days ago without following the rules since that day I have corrected the error of my ways , I apologize for this bad start ! ( I guess I don't read directions very well ) anyway does anyone have any Ideas , the system is a hydrotherm kn-4 with taco 1 hp circulator pumps and danfoss non electric zone valves , there are 12 buildings and this one banging is the smallest like I said I checked the obvious , is it possible the pumps are to oversized ? I'm going today to check each unit to determine if all 12 zone valves are installed in the right direction , thanks any ideas would be appreciated


 you may find that the flow is going backwards causing the danfoss valve to slam making a hammering effect. I had a school where the supply and return had been reversed above a hard ceiling. We had one area that hammered that was the problem. If this is the problem when correcting the problem take the control valve apart and check that the rubber seat is still intact or still there.


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## plumbthis (Sep 12, 2013)

We ended up shutting down the building and repiping the supply and return with the flow going the opposite direction ( obviously the way it was on the original boiler ) and silence , 1 out of the 12 apartments the heat never shuts off so we are changeing that zone vale today , like Wyrickmech suggested to check all the slamming probably ripped off or damaged the danfoss rubber seat washer , thanks


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