ok to cut circulation to all radiators?

serendip

Quick version: Is it ok to close the valve that controls the flow of hot water to both the upstairs and the downstairs radiators?

Long version: I believe my heating system is semi-sealed. All the radiators are controlled by individual thermostats, except the two in upstairs bathrooms. There are two valves in the hot press controlling circulation to the upstairs and the downstairs radiators. The boiler also provides heats the hot water.

If I were to close off both the valves in the hot press, then the only circulation through the boiler would be the hot water tank circulation.

I'm concerned that this might either damage the pump or otherwise damage the system.

So: Is it ok (or not) to close both valves, and use the boiler solely for hot water? Or should I use the immersion heater if no heating is needed.

(And a second question: Is it really the case that using gas for hot water is cheaper than electricity? I know the kWh price is cheaper, but there is considerable heat loss through the vent, in heating the boiler itself, and also in the pipes between the boiler and the tank.)

Many thanks!

Outkast_IRE

serendip wrote: »

Quick version: Is it ok to close the valve that controls the flow of hot water to both the upstairs and the downstairs radiators?

Long version: I believe my heating system is semi-sealed. All the radiators are controlled by individual thermostats, except the two in upstairs bathrooms. There are two valves in the hot press controlling circulation to the upstairs and the downstairs radiators. The boiler also provides heats the hot water.

If I were to close off both the valves in the hot press, then the only circulation through the boiler would be the hot water tank circulation.

I'm concerned that this might either damage the pump or otherwise damage the system.

So: Is it ok (or not) to close both valves, and use the boiler solely for hot water? Or should I use the immersion heater if no heating is needed.

(And a second question: Is it really the case that using gas for hot water is cheaper than electricity? I know the kWh price is cheaper, but there is considerable heat loss through the vent, in heating the boiler itself, and also in the pipes between the boiler and the tank.)

Many thanks!

Ok its hard to give you an exact answer you believe your system is semi sealed so this would mean you still have a tank in the attic with a non return valve fitted on the cold feed and the vent from the heating system is blanked.
If this is the case and your system is semi sealed then as such you should be ok to turn off the two valves , personally i wouldnt as if they are the standard wheel head valves there is a chance they will stick in position if left for a period of time , cant you just turn off the rads at the radiators.
Yes the gas should work out cheaper to heat the hot water as long as there is a cylinder thermostat fitted and your only heating the water as needed. Have you ever watched the esb meter when an immersion is turned on!!! it spins pretty quickly!!

JohnnieK

[QUOTE=
Yes the gas should work out cheaper to heat the hot water as long as there is a cylinder thermostat fitted and your only heating the water as needed. [/QUOTE]

If you fit a cylinder stat make sure to fit an automatic bypass valve too. If the cylinder shuts down the pump will be dead heading and could damage to pump in time. The automatic bypass will regulate the correct flow from the flow to the return when the system is cycling.

Outkast_IRE

JohnnieK wrote: »

If you fit a cylinder stat make sure to fit an automatic bypass valve too. If the cylinder shuts down the pump will be dead heading and could damage to pump in time. The automatic bypass will regulate the correct flow from the flow to the return when the system is cycling.

ya good point if both heating and hot water shut off then you will be dead heading unless your boiler has a built in automatic bypass

serendip

Outkast_IRE wrote: »

ya good point if both heating and hot water shut off then you will be dead heading unless your boiler has a built in automatic bypass

Thanks.

I believe there is a bypass. There's a copper pipe connecting what looks like the feed from the boiler (it feeds the hot water tank and the two radiator circuit groups) directly to what looks like the return. There's a valve on it, in the open position. so I think I'm ok.

Many thanks.