Hey all, Sorry if this question has been asked before. We've had a AquaTherm system for the last couple years. I'm looking at replacing it with a more modern, lighty-used boiler. What are the concerns, technicalities, challenges, etc., for moving from a pressurized to a non-pressurized system? I'm obviously a novice, and I'd like to make sure it will work before making the purchase. Thanks!
Going from pressurized to non-pressurized
- Thread starter WindyHills
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hobbyheater
Minister of Fire
Some pictures would help.
Is the Aqua Therm electric , wood , coal, oil , propane , natural gas ?
Do you have storage?
Is the Aqua Therm electric , wood , coal, oil , propane , natural gas ?
Do you have storage?
Hey! Here are a couple of not-great photos of my set up. The AquaTherm was a wood boiler. To be honest, it’s never seemed to work quite right. The guy I had install and work on it could never get the temp and pressure dialed in for whatever reason so I regularly had major boil-overs. I’m hoping a non-pressurized wood boiler (if it works with my system) will be less cranky. Again, I’m a novice. Thanks for your thoughts!
![[Hearth.com] Going from pressurized to non-pressurized](https://www.hearth.com/talk/data/attachments/316/316210-0b794e6e4e979d1bfca44d8ecec2e8c7.jpg?hash=OPahWVvUST "[Hearth.com] Going from pressurized to non-pressurized")
![[Hearth.com] Going from pressurized to non-pressurized](https://www.hearth.com/talk/data/attachments/316/316211-044a3703da69935ae90a19f2f3156684.jpg?hash=0444ugZ_x1 "[Hearth.com] Going from pressurized to non-pressurized")
![[Hearth.com] Going from pressurized to non-pressurized](https://www.hearth.com/talk/data/attachments/316/316212-1957166d8a85f63e32941106cc21274e.jpg?hash=ZXfzPszv2B "[Hearth.com] Going from pressurized to non-pressurized")
Thats a boiler...?
No wonder it never worked.
Pressure tank is way to small,no insulation around the boiler
your underground lines leave everything to be desired
Personally i have built only one system,my own. But i would scrap everything and start over
What water heater are you going with?
No wonder it never worked.
Pressure tank is way to small,no insulation around the boiler
your underground lines leave everything to be desired
Personally i have built only one system,my own. But i would scrap everything and start over
What water heater are you going with?
Yeah, it's actually a pretty standard AquaTherm boiler. You can find them all over Facebook Marketplace (at least around where I live) for around $1,000, give or take. 60 gallon water jacket around a firebox. It had insulation until its final meltdown, after which I tore it all off. (It was a water-soaked mess.) It worked well when it worked, but it was more of a headache than anything else. As far as I know, the company is now defunct.
Ignoring the old boiler, I'm trying to figure out if a relatively new Woodmaster 4400 (non-pressurized) would work with my in-floor piping (somewhat visible in the pic) and plenum heat exchanger.
Final Note: Scrapping everything and starting over is not an option. I like wood heat, and have a ton of free wood to burn, but my wife would not be on-board and I'm not going to get divorced over a furnace.
So it's this or propane.
Ignoring the old boiler, I'm trying to figure out if a relatively new Woodmaster 4400 (non-pressurized) would work with my in-floor piping (somewhat visible in the pic) and plenum heat exchanger.
Final Note: Scrapping everything and starting over is not an option. I like wood heat, and have a ton of free wood to burn, but my wife would not be on-board and I'm not going to get divorced over a furnace.
So it's this or propane.
sloeffle
Minister of Fire
If you do one thing, I'd definitely replace the underground line set. Any idea what your degree drop is from the boiler to the house ? I'd assume it's a lot.
To answer your question, you are doing to need to "separate" the unpressurized side and the pressurized side via a plate exchanger. No different than using a plate exchanger to make hot water. The furnace plenum can be fed from the unpressurized side after your plate exchanger.
My assumption is, for the current setup you are running boiler water through your in floor loops. That's a big no no because all of the particulates from the boiler will end in your floor loops. After you unhook your floor loops from your current setup I'd try to find someone to flush them out if possible.
To answer your question, you are doing to need to "separate" the unpressurized side and the pressurized side via a plate exchanger. No different than using a plate exchanger to make hot water. The furnace plenum can be fed from the unpressurized side after your plate exchanger.
My assumption is, for the current setup you are running boiler water through your in floor loops. That's a big no no because all of the particulates from the boiler will end in your floor loops. After you unhook your floor loops from your current setup I'd try to find someone to flush them out if possible.
Hey @sloeffle!
Thank you! That's the information I was looking for. I don't have an exact number, but the degree drop hasn't been terrible. I've been able to keep the house a nice, even 75 and haven't burned through as much wood as I was expecting. The boiler is pretty close to the house, so I think the short run has helped.
What I hear you saying, just to confirm, is that - yes - this will work with the plenum as long as I have a plate exchanger. But - no - it won't work with the in-floor tubing (which is fine ... that's never really worked anyway, which is a whole 'nother situation).
I appreciate your help and guidance!
Thank you! That's the information I was looking for. I don't have an exact number, but the degree drop hasn't been terrible. I've been able to keep the house a nice, even 75 and haven't burned through as much wood as I was expecting. The boiler is pretty close to the house, so I think the short run has helped.
What I hear you saying, just to confirm, is that - yes - this will work with the plenum as long as I have a plate exchanger. But - no - it won't work with the in-floor tubing (which is fine ... that's never really worked anyway, which is a whole 'nother situation).
I appreciate your help and guidance!
sloeffle
Minister of Fire
You don't need a plate exchanger if you are feeding the air-water HX in your furnace plenum. You would need a plate exchanger if you were to hook up the pressurized in-floor heating. Essentially, "one side" of the plate is pressurized, the "other side" is not. Here's a link to the install of my G4000 ( non-pressurized ). The pics in my thread should answer any of your questions.
My guess is, the in-floor heat doesn't work correctly because of your current setup. In the link in the previous post you can see how to correctly set that up.
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