Worcester Bosch 24cdi heating drain down- hot water?

[churchilldog]

I have a Worcester Bosch 24cdi boiler, I need to drain down the heating to add a new radiator into the system- quite happy doing all this and refilling.

BUT, once I have drained down the central heating, can I still switch on a hop tap to call for hot water or would this cause some damage to the boiler- I am thinking possibly the heat exchanger may get too hot?

Thanks,

CD

 

[OLLIE20]

Generally not good to run with no pressure, if boiler high up on system will o/ht anyway, are you adding complete new rad or replacing one like for like?

 

[hav it]

i dont know really why you would want to do that,and the answer is no, low pressure on the ch side will prevent the boiler firing hw mode.

 

[churchilldog]

Adding complete new rad and pipework. Just a really small one to sort a cold spot.

When I refill I will be adding inhibitor and boiler noise reducer.

I thought boiler pressure only referred to the CH side?

 

[churchilldog]

i dont know really why you would want to do that,

In case I need to wash my hands!

 

[OLLIE20]

It doest but its the CH water that heats your DHW through the plate heat exchanger (silver like sardinde looking thing) behing control panel, the job shouldnt take more than a day should it????? cant you last without HW for that long??????

 

[OLLIE20]

Why the noise silencer????????

 

[churchilldog]

Why the noise silencer????????

It developed a whistle when on CH a couple of years ago. Limescale in the HE. The noise reducer kept it quiet then, so its going back in now!

 

[OLLIE20]

Well if it worked for you before, cheaper than replacing heat ex i suppose

 

[churchilldog]

Well if it worked for you before, cheaper than replacing heat ex i suppose

Yes because I caught it early it stopped the problem getting too bad. Early reactions save lots of money!

 

[bengasman]

...When I refill I will be adding inhibitor and boiler noise reducer...

That would suggest you have a problem with the boiler already. How ofthen do you need to top the system up?