Vaillant Condenser strong enough?

[matt222]

Hi all,

I have a problem with my current old back-boiler system.

If I have all my 8 radiators on at one time, the most important one ( downstairs front room -700 X 2000 single rad ) does'nt heat up properly. It is hot around the top and edges but gets less hot towards the bottom. It is a brand new radiator that was fitted only last week and only heats up properly if 3 other rads are switched off.

I am considering a new, more economic and efficient system -Vaillant Condesing boiler. Would a new boiler solve the problem?

 

[plumbnuts]

You need to check if you have a single pipe system. This could cause the problem that you have and would also not be suitable for the installation of a new boiler.
Steve

 

[matt222]

How do I check - what am I looking for ?

 

[plumbnuts]

With a single pipe system the hot water from the boiler goes into the first rad on the system and then out and through the next and so on. If the system is not balanced there is not enough hot water left to serve the rads at the end of the system. On either system check the valves. One end of a radiator you should have either a thermostatic valve or a valve that shuts the rad down. The other end should have a cap that just spins when turned. Pul off this cap and close the valve by turning the spindle with a spanner. Once full closed open the valve about 1 turn. Repeat this on all rads and get back to me.
Steve

 

[matt222]

Thanks Steve,

Right, I have, as you say both types of valves - one that shuts down and one that has a dial you turn with pliers.

I have tried to balance the system by closing both valves on either side of each rad and then opening them both just slightly ( except for the rad I am trying to get hot, on which I have valves on both ends fully open. )

To recap, I am looking at my upatairs rads now and see only one pipe going in at each end. Is this then a single pipe system that is unsuitable for the new boiler ?

Huge thanks for this help.

 

[Deleted member 261]

larger radiators will never get hot in the middle bottom of the radiator. When you say the top gets hot is it as hot as the other rads some pics might help