by pass domestic heat coil on oil boiler with electric water heater

[Clinten]

Hi.
my fiance and I just moved into a home with a burn ham oil fired burner that has a domestic heat coil. There is a ball valve on the inlet side and the outlet side of the heat coil. What I would like advice on is after I install the electric water heater should I drain the domestic equal should I remove it or just leave it alone. Thank you in advance for your comments and help.

 

[Hydronics]

I assume you intend to use the tankless coil in winter and the electric in the summer, correct?

 

[Clinten]

I assume you intend to use the tankless coil in winter and the electric in the summer, correct?

No I will be using the electric all year

 

[Clinten]

I believe if I remove the lo/diff wire on my aquastat it will turn off the instant coil and I can shut off the water going to it .

 

[velvetfoot]

I'm no expert, but if you don't drain it, with the new piping and valves, etc, is there a way that the coil could be isolated and be constrained from expansion? Do those coils have a relief valve? I'm not familiar.

 

[Hydronics]

I would drain it if you don't intend to use it again, I'd be concerned with the water becoming stagnant and contaminating the water from the tank.
Personally, I would plumb them in parallel and use the tankless coil in winter when the boiler will be in use anyway. Use the electric in summer and shut down the boiler. -Maybe I don't have the whole picture of what you're trying to accomplish.
Another option is an indirect tank heated by the boiler which could have electric also for summer use only.

 

[maple1]

I would also drain it, rather than leaving water in it.

I believe if I remove the lo/diff wire on my aquastat it will turn off the instant coil and I can shut off the water going to it

I'm not sure what you mean there - you can't turn just the coil off. If the boiler is hot, the coil is hot. Will you be shutting down the boiler when not using it for heat? (summer?)

 

[Hydronics]

Yes, shut off boiler in summer and use only electric. Again, I'm not sure what he's trying to accomplish though. I suggested coil in winter because it will likely produce more btu/$ than electric when boiler is in use.

 

[peakbagger]

The manufacturer may offer a block off plate so you can remove it. I was told that it should be drained but left open. I was also told that at some point it could fail flooding my basement unless I removed it and installed the block off plate. I currently its isolated on the supply side