Outdoor Wood Furnace Info

All-Purpose OWF Discussions => Plumbing => Topic started by: ST98 on February 16, 2015, 04:00:21 PM

Title: The water hammer, maybe
Post by: ST98 on February 16, 2015, 04:00:21 PM

This is the second year with the OWB.  Couldn't be happier. I noticed about a month ago what seems to be a water hammer when one of the zone valve closes.  I don't remember it happening any other time.

Here is the lowdown.  The oil burner has one pump and two zone valves. I have a second pump on my furnace that runs 24/7 from my water to water heat exchanger.

When one zone calls for heat the furnace pump comes on and off with no incident. When two zones are open with pump running and one zone valve closes while the other is still open I get the bang.  I've got two air eliminators on the pressurized side.  I don't really have any thoughts on why because it just started doing it or I just don't have any thought.

Thanks

Title: Re: The water hammer, maybe
Post by: LittleJohn on February 17, 2015, 06:31:20 AM

You are not pump against one of the zone valves are you??  Forcing it shut or creating a vaccuum, causing it to close loudly

Title: Re: The water hammer, maybe
Post by: ST98 on February 17, 2015, 02:25:58 PM

I'm not sure what that means?  Nothing has changed since they put the oil boiler in 19 years ago, other than adding the OWF.  I just never heard the problem before. I did secure one pipe better and it has seemed to be less of a bang but still there.

Title: Re: The water hammer, maybe
Post by: LittleJohn on March 04, 2015, 06:26:47 AM

...do you have an expansion tank in the system, on the pressurized side, as it may have gone out and that is causing your noise.

Title: Re: The water hammer, maybe
Post by: ST98 on April 08, 2015, 06:38:58 PM

I do have an expansion tank on it. Is there away to check it? 

Thanks

Title: Re: The water hammer, maybe
Post by: fireman69lfd on April 08, 2015, 07:48:36 PM

If your owb is plumbed straight into your oil boiler without a heat exchanger, that is your problem. Zone valves can only stand so much slam from the volume and pressure from the owb. I had the same thing happen to me after 2 years from the dealer installed startup. Dealer said I would not need an expencive heat exchanger for my install to work with a 2 story. He was right, it worked great for a couple of years then I ended up replacing 5 zone valves and adding  a plate exchanger. Hope this helps.
Just another point, I had a 007 on my oil boiler and an 0011 on my owb

Title: Re: The water hammer, maybe
Post by: mlappin on April 08, 2015, 09:55:31 PM

FPHE's are not that expensive compared to not doing it right the first time.

Title: Re: The water hammer, maybe
Post by: slimjim on April 09, 2015, 03:12:49 AM

 :post:Exactly Marty!

Title: Re: The water hammer, maybe
Post by: ST98 on April 09, 2015, 02:50:31 PM

The knowledgable people on this site steered me to the correct install so I have an exchanger.

I have oo7 on the oil furnace and then a grundfos circulator pumping water through the oil furnace 24/7 back to the heat exchanger.  Oil burner circ only comes on when there is a call for heat.  If only one zone is open with oil burner circ running it doesn't do it. It only happens when both zones are open and one closes,  then bang.