Drained CH but now no HW

[Burgo99]

Hi, I drained down my central heating over the weekend as I need to replace the radiators. They are very old, corroded around the valve fittings and generally on their last legs.

Went up into loft and isolated the feed to stop the system filling up, then drained the CH system.
Currently, still like that as I am removing rads and capping at the valves for time being.

But, I have now noticed the central heating pump is "running" when the programmer asks for HW. Also have just discovered we have no hot water.

Is it obvious what I have done wrong, as its not to me ?

 

[stem]

If your system includes a hot water cylinder heated from the same boiler as the radiators, then you will have also drained the coil inside hot water cylinder responsible for heating it. Most systems these days use the same pump for hot water and heating, with diverter valves directing the water from the boiler to where it is needed.

Also, depending on the layout of your system and how you have drained it, the boiler may also be empty. It's not a good idea to operate an empty boiler, or run a pump dry.

If your hot water cylinder is fitted with an electric immersion heater, provided that the cylinder supply tank is still in use, you can use that until the system is refilled.

 

[Burgo99]

Hi, yes I have a 3 port valve so the pump being used for both does make sense.
Originally I was only going to drain down for the day and then refill once I had my rads off the wall. Unfortunately, something else came up and so never got round to refilling system. Ive drained before but always refilled the same day.

Will keep fingers crossed I have not done any damage, and will refill tonight when home.
Thank you

 

[Hot&Cold]

If your hot water cylinder is fitted with an electric immersion heater,

best answer,safely close down the gas system and use the immersion heater.Hopefully one is fitted and works correctly

 

[Burgo99]

thank you for the replies.
Went home and tried the immersion heater - outcome, I now know my backup for hot water does not work !
At least I know during a period where I can remedy this.
Will replace the immersion.
So I then closed down all rads and refilled and bled air.
Happy days, have HW again.