High tech solution to blocked microbore

We have recently been working for a client who lives on a housing development that was built in 1999. The whole of the development was fitted with a heating system that used micro-bore (10mm) plastic pipework for the last 2-3m of pipework before it was attached to the radiator valves.

The systems were fitted with low quality hot water cylinders and boilers, which have in turn, been replace. We replaced the hot water cylinder about a month ago.

This style of installation, which is now 18 years old, has not worn well. Large amounts of debris have collected in the small bore pipes leading to the blocking of one radiator after another. In this house 5 radiators were effected; this is in addition to the 3 radiator done a few years earlier.

We have worked with blocked radiator pipes in the past and have taken the approach of firstly flushing each individual radiator and pipework and then in that’s not enough, rodding the pipework with a wire pipe cleaner. Unfortunately this didn’t prove to be effective and so the decision was taken to replace the 10mm pipework with 15mm.

File 29-05-2017, 17 48 18The clients cleared their bedroom and landing of all furniture and carpets and we set about lifting floor boards to access the supply pipework. The next part of the work was to cut up the weyroc to allow new pipework to be connected to new 15mm radiator valves.

Once again the flooring was carefully cut with a vacuum linked circular saw which was effective in reducing the dust created. 2017-05-18 11.18.19



The previous 10mm pipes were pulled through the walls and capped off. The new pipes were notched through the floor joists and secured.

Once the pipe work was replaced the system was refilled and another cleaning additive added to finally flush out the remaining debris. The product was a very severe acid that could not be left in the pipework as it would have a detrimental effect on the aluminium alloy heat exchanger located inside the Worcester boiler. 2017-05-20 15.10.53

Therefore before the final balancing could take place the system was thoroughly flushed through with clean water until Ph7 was achieved, this was measure using Litmus papers.

Hydronic balancing

The next part of the work was to balance all the radiators so that an equal amount of heat reached each room. In the past this has been done using the skill and experience of the plumber who would go round the house adjusting “lock shield” valves as each radiator warms up. Alpha3[6]Grundfos, a leading domestic pump manufacturer have devised a more scientific system where the pump monitors the pressures on each radiator in turn and then tell you where to set the lock shield valves.

The pump is fitted with a detachable remote reader which collects the pressure and flow data and transmits it via Bluetooth to your App on your phone.

Once the set up data has been entered and the base flow calculated its relatively simple and quick to set each radiator. File 29-05-2017, 18 14 53The image below is directly from the iPhone App which as you can see is a dial which shows the correct flow value when the radiator is balance with others in the system.

The net result is a full balanced system using a highly efficient pump which Grundfos claim could save you up to 20% of your heating costs as well as savings from running the pump which is the most efficient pump in its class.


More details are available at Grundfos’s website :http://bit.ly/Mac-Grundfos

Finally our client left us a great review on Checkatrade – 

Although this work was quite intrusive Richard carried it out with minimum mess and disruption to our water supplies. Once the pipes were replaced he refilled and bled our heating system and balanced our radiators using the latest Grundfos Alpha 3 pump, which allows precise balancing of the radiator flows using a mobile app. Very neat. He also sorted out a long term electrical problem I’ve had with the heating for years. Once again excellent job. Thank you. Mr L. Whickham

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