Outdoor Wood Furnace Info

All-Purpose OWF Discussions => Plumbing => Topic started by: gmmaxim250 on August 27, 2016, 07:22:36 PM

Title: Water to Water Heat Exchanger
Post by: gmmaxim250 on August 27, 2016, 07:22:36 PM

Hello,
I think my water to water heat exchanger is shot.  A lot of mineral buildup on the outside and we seem to run out of hot water from time to time.  I am also thinking it might be time to put a new hot water heater in since I don't know how old this one is?  I am afraid that the tank has become filled with a bunch of sediment, therefore cutting down on the storage space inside of the tank...any thoughts?  I also wonder if the electric hot water heater is the best way to store hot water?  Any ideas?  Thanks...

Title: Re: Water to Water Heat Exchanger
Post by: RSI on August 27, 2016, 10:04:19 PM

If may be able to clean out the heat exchanger. Is is a flat plate type? If so, what size is it? If it is a 10 plate you would be better off just replacing it. If 20 or more it is worth trying to clean.

Electric water heaters are a lot better than gas for storing hot water because they are fully insulated. The bottom and center tube on gas models lose heat.

Electric are a lot worse for sediment buildup though.

Title: Re: Water to Water Heat Exchanger
Post by: gmmaxim250 on August 28, 2016, 02:05:23 PM

No, it is a tube type, might have to replace it, though I am going to try flushing the tank first.  Just seems to not be retaining much hot water...could even be pump on furnace, but I will work from hot water tank out.

Title: Re: Water to Water Heat Exchanger
Post by: RSI on August 28, 2016, 07:03:07 PM

It is a sidearm?
To find out if it is the boiler pump / loop flow problem, check the boiler water pipe after the heat exchanger. It will be a lot colder than before  if it is a flow problem. If you have an electric water heater and hard water you probably have a lot of sediment in the tank. Cleaning or replacing a sidearm may not last a long time if it is.

If the above is true, I would switch to a plate heat exchanger instead. You would have to probably clean it every year if the water is real hard.

Title: Re: Water to Water Heat Exchanger
Post by: gmmaxim250 on September 01, 2016, 09:09:40 PM

Yes, it is sidearm.  A couple of days ago, I flushed the hot water heater, and I pulled the the pressure release valve to try and make sure tube wasn't blocked.  Since then the temp and longevity of the hot water has been fantastic. 

Title: Re: Water to Water Heat Exchanger
Post by: RSI on September 02, 2016, 07:19:04 PM

There was probably some air trapped at the top of the sidearm.