Derek and I have been very busy educating people about expansion vessels and fixing boilers.
If your boiler is loosing pressure on a regular basis and you have to keep topping it up via the filling loop it’s MOST likely that there is a problem with your expansion vessel.
In a pressurised heating system such as a modern combi, the water in the radiators is pressurised in a sealed system. Like all water, when the circulating water is heated, to provide the heat in your radiators, it expands. When it expands it needs somewhere to expand to and this is where the expansion vessel comes in. The expansion vessel is filled with pressurised air at the same pressure as the system so that it retains a certain volume. Once the boiler starts heating the circulating water the expanding water is forced into the expansion vessel and compresses the air in the vessel to thus allows vessel to accommodate the expanding water. When the system cools down the reverse occurs.
Problems occur when there is no or very little compressed air in the expansion vessel. When it doesn’t have any air in it is when it fills with water and water is NOT compressible and so doesn’t provide a space for the circulating water to expand.
What happens next is key; the pressure increases in the system and the pressure relief valve opens as a safety device to expel some of the excess volume. This can be seen as water dripping from the small copper pipe at the back of the boiler, usually in the back yard.
When the system cools and the circulating water retracts to its original volume there is less water in the system because some of this water has drained out of the pressure release valve. This results in lowering the pressure and sometimes the boiler will shut down as a safety measure because of low pressure. The user then adds water via the filling loop and the whole process begins again.
Some “plumbers” will say there is a small leak or that its normal to have to keep topping up your boiler – THEY ARE WRONG!!
The expansion vessel is full of water and needs to be serviced.
Most manufacturers service manuals state that the expansion vessels is serviced on a regular basis.
So if you are finding that your system water constantly needs replenishing then it most likely your expansion vessel, which is a relatively straight forward job for a busy bee 🐝.
Progressing on now with great gusto, our roofers arrived on site this week to start the roofing work to cover the structure in Welsh slate.
They have hand selected the best slates that were taken off and mixed them all up in a random fashion so you can’t tell if they were facing north or south. The remainder will be sourced from a local reclamation yard and cut to size the match the original slates.
After a 10 week wait we finally saw the arrival of the oak trusses – very excited and impressed 🤪
Unfortunately they arrived on a 65ft artic but with the aid of a neighbouring farmer were carefully transported to site ready to be lifted on by the 14T crane.
Lady Luck really looked down on us as we had a great window of fine weather until almost complete when the heavens opened but by that time we had the trusses protected with polythene and we had complete most of the roof structure including the insulation.
Our team of roofers arrived bang on time to “black out” the new roof and now we are completely watertight able to continue with the internal electrical and plastering work.
Along with the underfloor heating, we have been calling on our construction skills to fit a series of steel supports for the new green oak trusses that are due next week.
The next stage of the work is to remove the existing roof structure and fit the new oak trusses which we will be bringing in with a crane.
Above is an example of how the trusses will look.
With the stone sub base in place and nicely compacted down we are now ready to start the prep for the concrete. With it being such a big area (11m x 5m) we have split it into two bit size chunks and shuttered these areas so these can be poured first. The concrete is due for delivery on Monday.
In preparation for a new underfloor heating system we have been excavating the floor down to a depth of 450mm and then back filling with sub base (recycled road planeings). The next stage is to lay the 100mm reinforced concrete… more to follow #recycling #reinforcedconcrete #underfloorheating
You wouldn’t expect a gas engineer to be a good brickie but the finishing elements of the job are just as important as the gas safety when you’re delivering a complete package.
Derek’s been a busy bee this morning. Luckily he’s small and can get into tight spaces so it was no trouble for him to bend some copper pipe and fit it under a boiler to supply a new garden tap.
There really is not limit to Derek.s abilities or the type of work he will do. Lots of people need a garden tap and Derek was happy to oblige.
If you need an outside taps for these hot summer days to fill the paddling pool for the kids or just to water the garden (unless there’s a hose pipe ban) call Derek and he’ll gladly fit one for you.
In other news – there’s a terrible skills shortage in the plumbing industry, find out more at : http://bit.ly/2tDuXQe
Derek’s been a busy bee this week looking at flues. At one property, when we went into the loft to inspect the flue, we noticed that the flue hadn’t been screwed together properly and that there wasn’t enough brackets on the flue pipe to hold it in position. The picture on the left shows another section of the same flue which has been fitted correctly. Note the brackets AND screws holding the parts together.
The problems is not that its dangerous NOW, but we have to consider what might happen in the future. If something or someone was to inadvertently interfere with it, the parts could become dislodged and this would allow products of combustion into the house, this in turn may get into the boiler causing it produce carbon monoxide, which of course is deadly. Derek and I determined this to be “At Risk”* and with the owners consent disconnected the gas supply so that it simply couldn’t be used. Documents were completed and issued to the home owner.
By chance, the next day, Derek and I had another call from another customer who had, this time, had his boiler condemned by another Gas Safe engineer and wanted a second opinion as he was facing a bill of several thousands of pounds for a new boiler.
In this case the engineer had determined that the boiler had failed the “spillage test” and the “smoke pellet flue flow test” and had determined that it was “At Risk” and as such issued a Warning Notice and labelled the boiler as “WARNING – DO NOT USE”.
I carried out some tests myself and found them all to be OK, so I rang the gas fitter and asked him what he had found. He said that the CO2% was too low and that I should know that and that is why it’s unsafe. Therefore I rang Baxi to check the figures and was told that there is no published value for the CO2% and so the figure I had found of 6% was fine, not dangerous. I removed the Do Not Use notice and reissued the Home Owner Gas Safety Certificate.
The clients were delighted that they haven’t had to fork out over £2000 for a new boiler and are now confident that their gas appliances are safe.
Bee Safe folks !
* At Risk (AR) means – An “At Risk” installation is where one or more recognised faults are present which could constitute a danger to life or property without further faults developing – further reading available at :- http://bit.ly/beeARAR