Boiler safety during vacation?

Hi Everyone,

I have hot water radiant heating system.
Whenever we are out for a long time (vacation) my main water supply
is turned off. At summer time my boiler is also turned off but during winter
time I want my heating system to be on but main water supply to be off.
Question is:
Is this a safe way or I am creating a BIG potential problem (melted
boiler/house on fire) if for some reason boiler will loose pressure?
I think it will be a good idea to add “pressure switch†to the heating
loop which will turn off boiler in case of pressure drop in the heating loop.
If yes, where this switch should be installed (at the boiler outlet or return)?

Thank you,

- Vitaliy

heating

If the boiler is on, but the water system is off, any discharge of water from the boilet will cause a loss of pressure. If you have pressure sensing valve, that would turn the boiler off, then you could expect a frozen house when you return.

HJ,

I understand, I may find a frozen house but my question was:
What is the safest way to leave house unattended for a long time?
Of course, there is no way to be protected against everything but it is
better to add more preventive measures and to minimize possible damage.

- Vitaliy

heat

The only "safe" way is to leave it as if you were living there, but at its lowest temperature. If you want to prevent a water problem, the only way to do it would be to attach the boiler feeder ahead of all the rest of the house's plumbing and install a valve after it so you could turn off the house without affecting the heating.

HJ,

But what if problem happens somewhere in the heating loop itself
(leaking radiator, etc.)?

- Vitaliy

heat

You can never prevent all possibilities. Every situation has an upside and a downside. You have to decide which is most important to you, and also which scenarios are most likely to occur. If the heating system breaks you will have a flooded house, but if you turn off the heat when the pressure drops you could have a frozen house with multiple broken pipes. The things you are trying to avoid might not happen in your lifetime to your house.