The Honeywell ST699 is an excellent product when new, but over the years the settings back-up battery fails so that if there is a power cut -off only for seconds, the settings have to be reset.

If approved and you accept, you'll have a credit limit added to your PayPal account ready to use immediately.Item arrived all packaged intact and unopened part for an old boiler will be recommending and using this site again.

If your item is being delivered in the UK or Ireland, it will be delivered by UK Mail/DHL, Hermes or Royal Mail, with the exception of pallet items. It controls the timing of the hot water and central heating twice a day, but the best bit is that anybody can set the times without having to read any complex instructions!From the product page you can use Paypal Express Checkout which will take you straight to your Paypal account where you can login to complete payment or apply for Paypal Credit. The ST699 is an electronic central heating time control programmer that can be used on gravity primary, or fully pumped systems having separate heating and hot water temperature control. You can change your choices at any time by visiting Cookie preferences, as described in the Cookie notice. We had the wiring diagrams for both units, and we carefully worked out where the different wires went. If this is the first time you have used PayPal Credit, you will be asked to complete a short application form to apply for PayPal credit.

I'll go take a pic The two cables entering from the RHS are room stat wires - obviously no three core available so a pair of 1.

Just looking for something as low cost as possible that I can control via the internet connection if I'm away from the home. The thermostat cable will be between terminal 4 on new programmer and brown of CH two port valve, connect brown of the CH valve directly to terminal 4 so it excludes the now redundant thermostat cable. When I examined the old control unit, I noticed the battery inside was dead and leaking so badly that the connection to the circuit board had corroded and loosen off. Take programmer and back plate off, ignore the links between L, 5 and 8 as you won't need them on new programmer. It is not the cheapest one out there but it is fairly simple to install, reliable and easy to understand and use.