twin hot water tanks

[galway]

We have a small B & B and have two hot water tanks in the loft which are heated by gas boiler in winter and immersion heaters in summer. But when we have no guests in we only need to heat one tank yet both tanks outlets are connected via a T connecter to a common supply.
Is there any way of remotely switching one of the outlets so that only one tank is being used. If this can be done, how can I ensure that the gas boiler is only heating one tank?
Would appreciate any suggestions.

 

[Moz]

galway
you need to fit a valve

Motorized valves come in two flavours: 2-port, known as 'zone valves' (a simple open/closed piece of pipe), and 3-port (a fully controlled T-junction).

There are two varieties of 3-port valve, mid-position and diverter. With a mid-position valve the middle port is connected to flow from the boiler and the water is directed to port 'A', 'A and B' or 'B' as requested. With a diverter the boiler flow goes to either 'A' or 'B', but never both. Alternative names for these valves are (respectively) 'Y-plan' and 'W-plan', after the names Honeywell give to them under their Sundial Plan system.

you may need to get a plumber to fit this as it needs to be wired up correctly /building regs now ...