Domestic Hot Water

PaulC

I have recently converted to gas. I had a new hot water heater installed. I still have an oil fired steam heat system. I shut off the valve feed to the DHW coil, and the valve from the boiler. My question is; do I need to take any action/precaution before I fire up the boiler for my heat?

bustoff315

Firing up the heat

Shutting off the domestic hot water to the boiler won't have any effect on your heat.  Just make sure that you can see the water line in the sight glass, and if you know how to then check the safety on your low water cut off.

PaulC

DHW

The water for heat/steam is manual, I maintain the level. My concern was primarily having water trapped in the coil. Do I need to drain it, and leave it open?

bustoff315

DHW

It really makes no difference.  Personally, if you aren't going to use it anymore I'd just open up the DHW relief valve to take the pressure out of the coil.  You don't have to worry about completely draining the coil.  How did they pipe the new gas hot water heater?  Did they use a tee so the steam boiler coil could be used as a DHW backup in case anything ever happened with the hot water heater?

Also, there should be an aquastat on the steam boiler near the coil that would maintain temperature for DHW.  Make sure those wires are disconnected so the boiler doesn't run on those warm days you don't need the heat.

PaulC

DHW

Ah thank you very much! The water heater is T'd off and I can go back to the boiler if need be. I was wondering how to keep the furnace from firing to heat the water, I understand & found the wiring for the aquastat. Eventually the water in the coil will fully evaporate & that won't cause a problem I take it?