Freeze-up Protection

[jebatty]

Has anyone use a small, tankless hot water heater for freeze-up protection on a wood boiler system? Thought would be to operate it and the circ pump on a timer for a couple hours/day during times when I might be gone for an extended period during the winter. My system will stay above freezing for up to about 10 days, even with -10 to -30 outside. Thanks.

 

[Nofossil]

Has anyone use a small, tankless hot water heater for freeze-up protection on a wood boiler system? Thought would be to operate it and the circ pump on a timer for a couple hours/day during times when I might be gone for an extended period during the winter. My system will stay above freezing for up to about 10 days, even with -10 to -30 outside. Thanks.

I'm doing one of those as my backup heat. I'm assuming that whatever your backup heat source is, you could run the boiler circ from time to time for a few minutes and be fine. Maybe a low-temp aquastat?

 

[jebatty]

It won't be backup heat for me, just to keep the system above freezing. My thought also to use a low temp aquastat.

 

[Sawyer]

Hey Jim,

Looks like that -10 to -20 is a reality and you are sending it my way!

Keep warm, George

 

[Mushroom Man]

I was wondering about whether an oil-fired DHW (50 gal) tank with a sidearm would work to keep the rest of the system from freezing by turning on the circulator at fixed intervals. This is just to prevent freeze-up.

I'm not too worried about the storage, as it is in the basement and the oil furnace (the backup) can keep it warm down there.

I've been advised that the safest option for a vacation would be to drain the system or add a glycol mix.

 

[Tony H]

I debated and decided to add glycol to my system to prevent freezing since I know there will be times I will be out of town for several days. I also thought I could run the circulator and pick up some heat thru the exchanger in the forced air furnace the one thing I did not realize was that run the circulator and have it flow thru the whole system I would need a bypass around the termovar. Guess it was a good idea I put in glycol it will just be a little extra work when I have to drain the system to make a change.
On the other hand I did fill and drain the system several times (before Gylcol) testing the system and connections and it was not that hard but there are places where the water will be trapped and sit so you must look at your layout and see if any of those low areas are prone to freezing as then you may need to add another drain or blow the pipes out to remove the water from those areas.

 

[jebatty]

I have glycol in the Tarm. It's the system + 1000 gal storage that concerns me.

 

[Rugar]

I've purchaced the hydronic antifreeze (NO Burst) but now I'm unsure if I need it. I ran my pex three foot deep wich is way below frost depth for me. Only concern I would have is my EKO boiler and imediate plumbing in my outdoor shed. My primary loop will loop through my gas boiler return manifold and eventually my DHW via sidearm. My first thought is that will my underground pex pick up enough heat to keep the system from freezing and now I realize i'll probably add some heat from my existing boiler and possibly DHW. Am I right or should I put in the antifreeze I already have. Can I even send the stuff back or resale it.