One for the plumbers

[vmaximus]

Hi, I am in the process re-decorating the house and I want to take of three radiators. What I would like to know is, can I isolate the CHW but still use the domestic hot water . I have a Worcester bosch green star classic combi boiler with inline filter and stop valve fitted to the return side of the CHW. There is very little room to cut the C/H feed pipe but is there a small screw type isolating valve underneath the
boiler, can I use that and by isolating the C/H and by just using the DHW there is no chance of overheating the system and causing any damage. Thanks in advance for any info. Pud.

 

[123hotchef]

if the pressure in the heating circuit drops the boiler fill stop working full stop, can u turn the valves off at the rads and remove them that way?

 

[grim_d]

As above, close the valves at the radiators and remove them, then you can still use CH and HW.

When you go to refit, the system pressure will drop and you will have to fill the system to re pressurise it. This will be via the fill loop on your boiler.

 

[gaz1]

if you drain down the system no it wont run

if you take off the rads and close the valves off and fit the plastic cap on thermostatic radiators then yes

dont close the valves off underneath the boiler

 

[vmaximus]

Yes I could remove the radiators but I have had problems with the thermostat valves leaking before, that is why I wanted to isolate the full C/H system and just use the domestic side for a few weeks. I have drained the system down several times before and re-pressurised the system with the filling loop. My original idea was to cut the C/H feed pipe fit a isolating valve re-pressurise the remaining system and just use the DHW until I have completed the modernisation, but I don't want to cause any damage to the boiler by doing this. Pud.

 

[grim_d]

Get brass blanking caps for the valves to isolate any leaks. They have a rubber seal in them. A few quid from screwfix.

I use them when removing radiators just incase a trv is a bit sticky.

http://www.screwfix.com/p/bsp-blank-nut-x/39553 (check size!)

 

[gaz1]

if you dont have the caps the valves do open they can also vibrate open as well

 

[vmaximus]

Thanks chaps, I never gave blanking caps a thought, will order some straight away, seems a much easier way than I was originals going to do it. Pud.

 

[Kayos]

If you don't have at least one rad you could damage the boiler as it dumps the heat when you turn the hw tap off. Fixed a 2 year old boiler with big problems last week, thermostat broke so she turned all the rads off at both ends. New pump, air vent and dhw plate. Bosch are known for it as they run close to the limit

 

[Toleman]

Make sure you use rubbers!

They don't always come with them

 

[grim_d]

If you don't have at least one rad you could damage the boiler as it dumps the heat when you turn the hw tap off. Fixed a 2 year old boiler with big problems last week, thermostat broke so she turned all the rads off at both ends. New pump, air vent and dhw plate. Bosch are known for it as they run close to the limit

That's good to know.

 

[Woody.v8]

Make sure you use rubbers!

They don't always come with them

 

[vmaximus]

Thanks Kayos, I am only going to take off 3 downstairs radiators, the rest including the bathroom which is permanently open will be left connected. Pud.

 

[garethp]

Make sure you use rubbers!

They don't always come with them

And when you ask for rubber washers to fit the caps they probably wont have a clue so be prepared to look at the book and figure it out...