Our customer bought a fantastic building constructed in 1868, located in Carshalton, Surrey. Listed inside and outside, it was built to the requirements of the author Mark Rutherford (real name William Hale White).
Work starts here
It incorporates many interesting features, for instance the inside walls are three bricks thick, because Mr White required silence and solitude in his work.
Blue plaque
The chimneys were all internal to the building, to minimise heat loss. A Victorian eco house, no less.
We were asked to upgrade the existing installation of heating, which dated back to the 1980s. Although the radiators and pipework were in reasonable condition, the boiler had not been installed correctly and had been subsequently modified, rendering it unsafe.
This is where we started, with an old open flue ‘Chaff’
The boiler was a Chaffoteau et Maury unit, which the observant will note is a French boiler. It was quite an innovative design, with a copper heat exchanger and a mixing header, and the unit also had modulation control.
It is an ‘open flue’ appliance, and it was the implementation of the flue where the job fell down. The boiler instructions and British Standards call for a 600mm straight section of flue off the boiler before any bends, which must not be sharper than 45 degrees. Also the flue cannot pass adjacent to any combustible items. The installer had managed to contravene all three requirements on this job.
The flue cut through a wooden window. The brackets exist all the way up to roof level but the flue has been truncated and the original cap cemented back on top.
But to make absolutely certain the flue didn’t work properly, someone had subsequently removed most of the external vertical stack, thus destroying the natural draught in the chimney necessary for safe operation. Typically this would cause imcomplete clearance of combustion, and possible downdraught of combustion products into the room. All very dangerous, and when we checked, the customer mentioned that the boiler often locked out in high winds. So there we are, a lethal appliance.
Although the old boiler was sized at 37Kw, calculations showed that a 30Kw unit would be sufficient, so we installed a Worcester Bosch 30CDi regular boiler. Oversizing a boiler has no advantages, and is not recommended. As the building was listed, it was not possible to change pipework to provide heating zoning, so we suggested using the new 2014 Honeywell Evohome colour.
We could brick up the old flue because the new unit will vent unobtrusively below the window.
The system was comprehensively Powerflushed and Magnacleansed, using the latest equipment. The Norstrom Powerflush uses an integral heater to assist the desludging process, and the water is passed through the Adey Magnacleanse magnetic filtration system too, this removes 95% of magnetite on the first pass. This is the most comprehensive system cleansing- and we do it as standard. It takes time and investment in plant but it is the only way to guarantee the best result, a clean radiator system.
Powerflush and Magnacleanse in action
The Evohome colour was delayed until early April due to a problem with the manufacturing of the new version of Honeywell actuator – the HR92. For the last 12 years we’ve been using the HR80, the HR92 is cheaper, smaller and has a few more features. We have 200 HR92s on back order at the time of writing, or our order for this job was the first received at Honeywell UK, so we got the first stock!
Each valve is radio linked to the Evohome control. The radio network is a proprietary system not related to WiFi; therefore the range and reception is greatly improved. Even with three courses of brickwork on the internal walls range is not a problem in this house, and we’ve done much, much larger houses over the years with the earlier versions of this system (some of which are featured in other gallery posts).
HR92 Valve fitted
Each valve uses 2x standard AA batteries. When you use Honeywell valve bodies (which we do) you can expect a life in excess of 2 years from the batteries.
In all there were 18 radiators, so the programming was done on the kitchen table, as usual.
Only another 180 to do this month, assuming Honeywell get them to us
The Honeywell Evohome allows the owners to sub divide the heating into 12 areas across the house, saving money and improving comfort. They can also control the system on a room by room basis from their iPhone from any connected place across the World.
Finished exterior, old flue completely removed
New boiler system completed
- New Evohome all ready to go, Wednesday 16th April
Our customer was delighted with the new system; the boiler and 12 zone control will transform the comfort, and the economy of the heating.
12 heating zones, Hot water control, iPhone and Android connection. And just 5% VAT!
The new Worcester Bosch boiler will be covered by the manufacturer for 8 years, parts and labour, under the extended guarantee scheme facilitated by us.
