turning off water supply but leaving the boiler on?

bentz69

As a new homeowner Im still learning quite a few things. The family and I will be away for 7 days and the tempertures over here are dropping just below freezing at night time now. My home is well insulated.

I have a burnham v84 oil boiler for baseboard heating and hot water. I understand there is no perfect solution but I would like to minimize the potential damage if a pipe were to burst/leak while away if possible. I was curious if I could turn off the main water supply to the house but keep the boiler on. Obvioubly no one would be using the sink/shower/toilet and I will flush the toilets and open up the sinks to let any remaining water out before heading out. I would be leaving the thermostats set to roughly 50-55F so its possible baseboard heating could come on. Is that ok?

STEVEusaPA

Best would be to have a working low water cut-off. I have a low water cut-off and always have the boiler feed off. I also walk by my boiler twice a day (in and out) and look at the pressure gauge.
Water pipe break/leak can do considerable damage in minutes/hours.
Other options would be a freeze alarm and/or take advantage of the dry (alarm) contacts on most modern primary controls, and even have someone stop by and check.
For vacation I also shut off water main and gas into house, but leave on gas supply to generator.

Leon82

I have mine off. Observe it for a few weeks after you turn it off make sure the pressure is staying the same.

Gordy

If the system doesn’t leak leave it off. That way if it does leak the only water you leak is what’s in the system. However the boiler will dry fire if it does happen to leak, not good. a LWCO is pertinent to have for safety.

hot_rod

Any way to get a temperature alarm connected to let you know if the boiler fails? Or a prolonged power outage.

Smart wifi thermostats can also notify you or you can check in daily.

Or put antifreeze in the system.

The Axiom, or other brands of feeder units are another option, 6 gallon capacity and also alarm if that much fluid goes out. Either water or glycol.

Depends on how much piece of mind you want.

Or have a neighbor or friend check in.

bentz69

I don't have a low water cutoff so that's something I would have to look into. A freeze alarm is another option but right now I don't have one and we are leaving tomorrow. I have never noticed any leaks in the system.

I have a Wi-Fi thermostat for my air conditioner and I love it. Unfortunately my heating system works on line voltage and I'll have to convert to a 24 volt system before I can use Wi-Fi thermostats for heating.

So I guess the best option for me is just to kill the main water supply, leave the thermostats on 50 degrees and leave the boiler on.

The temperature setting on the boiler is at 170 f. Should I just leave this temperature alone or should I lower it to 140 or lower?

STEVEusaPA

I wouldn't lower the water temp. Couldn't you use your wifi thermostat to monitor the house temperature?

bentz69

Yes you're right, I can use the Wi-Fi thermostat to tell me the temperature of the house. But that is only good for AC so I wouldn't have any control over the Heat while away.

My heating system is kind of strange because there are no zone valves on this 3 zone system and there are no check valves built into the first or second floor piping or circulator pumps. So even when the heating thermostats are completely off, I still get very small amounts of heat coming from some of the baseboards on the first and second floor.

But at the moment I have turned off the main water supply to the house and I turned on all three heating zones just to test the system and boiler to see what would happen.

Adolfo2

bentz69 said:

As a new homeowner Im still learning quite a few things. The family and I will be away for 7 days and the tempertures over here are dropping just below freezing at night time now. My home is well insulated.

I have a burnham v84 oil boiler for baseboard heating and hot water. I understand there is no perfect solution but I would like to minimize the potential damage if a pipe were to burst/leak while away if possible. I was curious if I could turn off the main water supply to the house but keep the boiler on. Obvioubly no one would be using the sink/shower/toilet and I will flush the toilets and open up the sinks to let any remaining water out before heading out. I would be leaving the thermostats set to roughly 50-55F so its possible baseboard heating could come on. Is that ok?

I have a gas mod-con boiler with built-in LWCO. I shut off the house water main & boiler feed whenever we go away for more than 24-hours even in the summer.
My reason for also shutting off the boiler feed is to keep the boiler water from back feeding into the domestic due to pressure in the expansion tank. Yes, there is a check-valve but I'm pretty sure it isn't 100% perfect.

nicholas bonham-carter

You may need a real backflow preventer. Drinks made with boiler water would not be good for you!—NBC

mikeg2015

bentz69 said:

Yes you're right, I can use the Wi-Fi thermostat to tell me the temperature of the house. But that is only good for AC so I wouldn't have any control over the Heat while away.



My heating system is kind of strange because there are no zone valves on this 3 zone system and there are no check valves built into the first or second floor piping or circulator pumps. So even when the heating thermostats are completely off, I still get very small amounts of heat coming from some of the baseboards on the first and second floor.



But at the moment I have turned off the main water supply to the house and I turned on all three heating zones just to test the system and boiler to see what would happen.

With a relay, you can make it work on most thermostats. However you need to be able to set cycles per hour or differential targets so it doesn't short cycle.

I have a Lennox iComfort thermostats upstairs and downstairs controlling heat pumps and use relays to enable steam boiler as the aux heat (but not during defrost). I have outdoor temperature sensors and use balance point control.

mikeg2015

.. I have an electronic AND mechanic LWCO and leave my fill valve closed. When I replace the boiler, I'll move the electronic to the wet return.