Running central heating with no radiators

[ziggy]

Folks,

I am about to replace all radiator valves in my system plus replacing 3 radiators that have pinholed. A few weeks back I had some system cleaner in for a few days and flushed out. Seeing that I have to drain the system and disconnect all radiators I want to see if I can get any more sludge out of the pipework as its an old system.

If I cap off all the flow and return pipework, is it safe to run the system (with some cleaner in it) with no radiators so I can do one more flush of just the pipework?

Ziggy

 

[AllyBongo]

No because you wouldnt have a circuit then. If you want to do it leave 1 rad on, or link all the pipework when you take the rads off. Prob better cleaning with all your rads on tho

 

[maul]

the rads complete the circuit take then out and you have nowhere for the water to flow from the the flow to the return pipework
shutting down rads will force the flow through the other rads so you can do that in a sequence that makes sure every pipe gets a good flow though it
just make sure your boiler temp is turned down so you dont trip the overheat out and have to reset it .

 

[ziggy]

If I left one rad on or connected one flow pipe to a return pipe would it be best to do this on last rad in system i.e. would that ensure cleaner ran through all the pipework?

 

[AllyBongo]

Better just leaving all rads on, that way all the pipework is being cleaned. Add cleaner and leave for about a week. Run heating as normal, then flush it a few times. Prob get best result that way

 

[maul]

allybongo is right
by taking all rads except one off and trying to clean the system you are not getting any flow in the pipes splitting off to the missing rads.
you will just be cleaning the flow and return from that one rad to boiler and back
in reality that could be less than half your pipework depending where all the tees are in your system