We moved into a house recently which has micorbore piping throughout the heating system. This combined with the fact that the system has been extended twice over the years means that it is impossible to get hot water to the radiators at the furthest points in the system. Anyone know if it would be possible to add a pump to help boost the flow? We had underfloor heating in the last house which had one and it seemed to work.

have you tried rebalancing the radiators first?

have you tried rebalancing the radiators first?

Often overlooked.

Yes the heating engineers have tried this and power flushed the system

How old is your existing pump if you have one?

hi.. couple of questions first up..

what type of system do you have at the moment.. do you have no pump at all and relying on heat to move the water? or a pump that is nt working as you d like?

hot water likes to flow and will get anywhere.. so is there zero heat in the affected radiators..even when every other radiator is closed..if so the pipework is blocked at some point.. if there is some background heat in the radiator but its not getting hot then the whole system need balancing..

when you say they flushed the system did they do it properly or simply attach a machine and hope for the best or did they take each radiator off take them outside and flush them through as well as flushing the pipework via both flow and return?

it would be as rare as hens teeth for a system that presumably worked at some point to stop working for no good reason and a blockage is odds on the culprit.

Hi total shell..we have a valiant gas boiler with a seperate tank on the ground floor. The system was power flushed by British gas which I believe was done correctly. The radiators may work at the extremities of the system if other radiators are turned off (the exact combination seems illusive!). I’ve had different engineers out over the last 18 months and they do seem to agree the microbore piping may be an issue (as the house was extended twice). One suggestion has been to run a wider bore pipe to the back of the house.

. The boiler is about 16 years old so perhaps is flagging anyway.

do you have a pump at presnt?

the microbore pipework is only an issue when it becomes part or totally blocked making it even less effcient. most /all new properties the rads are fed with plastic microbore and i ve just done a large victorian villa with 15 cast radiators and much of that was done in micro bore.

aside from the micro bore you will /should have considerable lengths in 22 and 15 a point of conflict can be the udders where pipe size is reduced from a single 15 pipe down to half a dozen 10mm pipes.

for the price of a pump i d fit one if not. if that doesnt do the trick i d consider running new plastic at least to the most accesable/ furthest rads. in doing so you d be immediately aware of the condition of the pipework quality of the water.. the very first thing id do though is fit a filter.. fernox tf1.. this will lift any and all debris out and is an ongoing investment as it has no running costs and will last a lifetime.

Hi totalshell thank you very helpful. I believe (although impossible to confirm without lifting the floor throughout the house) that it is fully micro. We stay in a rural area and the same BG engineer who has serviced the system over the years is pretty clear on this as he can see the pipes at the boiler and manifold. Thank you for your advice.

PS. there is 18 radiators in the house