Central Heating that won’t cost the Earth
Cheap boilers can look tempting, but in my opinion it’s a false economy. A Worcester boiler might be £200 more upfront, but a cheap make could cost you that on one call-out. They are also easier to fit so I recoup a bit on labour costs.
Radiators have a life expectancy of 15 – 20 years, after which they may leak. On fitting new central heating or draining the system for any reason, flushing with a system cleaner and sludge remover, then adding anti-oxidant by Fernox or Sentinel is essential. It will slow the oxidation process, as well as making the boiler run more efficiently. Build-up of sludge and corrosion inside the boiler effectively insulates the internal pipes from heating by the burners, wasting energy.
Since April 2005 for gas and 2007 for oil, all new boilers fitted to UK homes have to be condensing boilers. This is a clever system by which energy is recovered from the hot flue gasses with a heat-exchanger. As the gasses cool, water vapour condenses out (hence ‘condensing boiler’), and the condensate has to go somewhere. A pipe needs to drain to the outside. Boilers can stop working if these become blocked with ice in cold weather. Hence you can save the cost of a call-out if the pipe is property insulated with foam lagging.
You can also save a call-out if you have reliable tenants you can educate about bleeding radiators. The top of a radiator may go cold because gasses dissolved in the water vaporise out. The gasses can be released with a little brass key which opens the radiator drain cock – the little square nut in one top corner. Gas escapes, and as soon as water comes out, the radiator is full and the cock can be closed. Alternatively automatic bleed valves are now available, see http://propertytribes.ning.com/forum/topics/automatic-radiator-bleed
If system pressure drops frequently it may mean there is a slow leak which needs investigating. Slight pressure drops due to release of dissolved gasses (see above) can be corrected by opening the cock on the boiler to the mains water. Instructions on how to do this should come with the boiler. It’s a simple enough job but I wouldn’t leave this to tenants as over-pressurising the system can cause problems.
If the property is well insulated the boiler will work less hard and last longer. Your tenants might last longer too. No-one likes being cold or paying high heating bills. The current standard required by building regs is equivalent to 270mm of fibreglass in the loft. Cavity walls can be insulated in the cavity. Solid walls can be insulated inside or outside, although you probably wouldn’t do this unless renovating. Draft excluders can be fitted. I prefer the heavy-duty type with a rigid rod containing a folded-over flexible plastic strip or a stiff brush. Here’s a link.
Finally a last word from Steve Griffiths, a Gas Safe installer of many years experience:
‘Baxi or Worcester for me but personally I prefer Baxi as the parts are better value over the longer term. Fit a magnetic filter at the same sime, include Fernox TF1, Magnaclean or similar and flush the system, and stick with a built in 24hr time clock for simplicity and happy days.
For a combi swap depending on where you are in the country, choose a Baxi 28 or 30 kw A rated boiler.