About the client
The boiler and hot water cylinder are located in the basement plant room of the 4 story building with the boiler flued through a lined chimney terminating above roof level. The heating header tank and hot & cold water header tanks were located within a section of the pitched roof of the attic area; this ensured that both hot and cold water supplies were correctly balanced. The head height in this attic is quite high which has allowed the majority of it to be converted into usable space. The nursery was keen to utilise the remaining space however the existence of the tanks were hindering this. For this and other design related reasons we therefore advised that the new heating and hot water systems should be converted to an unvented type which would allow the removal of the tanks. This would not only eliminate the risks of future leaks from deteriorating tanks but would also free up this valuable space for the nursery to use.
During the various site surveys prior to commencing work the nursery manager highlighted a number of ongoing issues, one of which was that the top floor radiators rarely heated up while the radiators to the lower floors were fine. We established that there was a large amount of air within the top floor radiators, this was later found to have been caused by a blockage in the outlet from the boiler header tank so as the staff had been venting radiators they were actually draining water from the radiators on the floor above as the tank could not make up the water. The blockage at the tank outlet was causing the pumps to draw air in through the open vent which was compounding the problem. Converting to unvented would solve this problem even though we would need expansion vessels, filling loops, new relief valves etc. it would be a far more reliable system and they would have heat in all areas of the building.
It was also noted that there was an issue with the hot water zone valve and it was later determined that the hot water cylinder controls were not functioning correctly. When the cylinder temperature dropped the valve on the primary circuit closed instead of opening and the water was subsequently then heated by the immersion heaters which was very in-efficient. When the water finally got to temperature the immersions cut out but the zone valve was operating in reverse. However fortunately this was a relatively easy fix and was resolved after the equipment installation.
It was agreed that we would first replace the boiler, hot water cylinder and associated equipment and any other system related problems could be addressed after it was all up and running. The main challenge we had to overcome was that the installation needed to be carried out over the Easter weekend in order to minimise disruption to the nursery. We only had 5 days to complete the job and all of our suppliers would be closed over this long weekend so we had to have everything required for the install (boiler, cylinder, pumps, pipe and fittings to name but a few items) delivered on the Thursday. Our hardworking team of engineers volunteered to work all the way through the bank holiday weekend to ensure the heating and hot water was up and running on time. The nursery was most accommodating and allowed us to start work draining down etc. on the Thursday while all the deliveries were arriving. There was also the matter of scaffolding that had to go up to allow us access to the chimney to fit the new flue liner; this was also carried out on the Thursday by the specialist contractor.
With the heating and hot water systems drained the boiler was removed as was the hot water cylinder. A new unvented 500 litre cylinder was installed with all the appropriate unvented kit and a secondary return pump which was another issue that we established had not been originally fitted.
The new boiler is a floor standing Potterton Sirius Three FS 110kW which we connected to the existing system using a plate heat exchanger. We recommend that plate heat exchangers are used on old systems in order to divorce the existing circulation water from the new high efficiency boiler equipment thereby protecting the boiler internals of potential debris contamination from the old pipework and radiators. We connect the radiator circuit to the secondary side of the heat exchanger and protect the plate with a magnetic filtration system fitted on the return line from the existing system (click here to read the news feature about this installation on the Boilermag website).
A new stainless steel flue liner of approximately 20 metres in length was drawn down the chimney and subsequently connected to 2 metres of ridged section on to the boiler as per the manufacturer’s instructions.
The existing controls were more than adequate to utilise and with the boiler connected and filled, the system was ready for testing. That’s when the next problem presented itself, a broken actuator on the heating circuit mixing valve. This was another relatively easy fix, as although the old actuator is now obsolete, we were able to source a new replacement Siemens head to fit the existing valve body.
With all systems now operating as they should the new pipework was insulated and the boiler suitably commissioned to safeguard the warranty. The new system will give the nursery peace of mind over the winters to come as well as being more efficient and therefore saving them money on the bills for heating and hot water.
Diane of Childsplay Nursery said:
“Following the recent project at Childsplay Nursery to improve our heating and hot water systems with a new boiler and all the technicalities which came with this, I feel very obliged to let you and your team at Enright know how impressed we are regards the support, Professional dialogue, workmanship and operations of the project from beginning to end. Your engagement and lead role in the project meetings, listening to our needs as a business and offering support for our current concerns with the old system and suggesting how you could implement the new boiler for us. I am aware that our ‘job’ was a difficult one given our business operations had a short window of time for such a large scope of works to be completed, as well as the style of the old 1800’s building. However you and your team put us at ease re managing the process of the project and when plans required some change very close to the start date for the works to begin, you and your team were very willing to identify the necessity for this and supported with agreed solutions.”
“Your team of heating engineers worked to very high standards, their professional outlook to support and help the customer to the best of their ability shone through; I would particularly like to say that Ronnie, Adrian and Jimmy were extremely positive about the whole project. their work showed the range of professional techniques and knowledge they have and they deployed their skills, problem solving techniques and design with great efficiency. They remained in contact at all times, worked diligently and were the tidiest maintenance contractors I have ever worked alongside. Given our business is for the Education and Care of the young child, I never once had to worry about safety issues and on this matter alone, I would highly recommend you as a company to other nurseries and educational establishments who require your expertise in Heating and Engineering projects.”
“I look forward to seeing your team again during visits under the maintenance agreement, I feel very confident that we will receive the best of care and attention from you in the future in order to keep our boiler working efficiently. Once again many thanks!”