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I need to replace my oil fired central heating boiler.My system is a gravity fed system and has no controls other than the boiler stat and some trv.I would like to make my system as efficient as possible without having to rip my house to bits to much.the boiler I have in mind is a Grant mutipass boiler installed in my utility room any plumbing mods would have to be confined to the utility room as i do not want to spoil my home as I have recently installed new kitchen and bathroom and redecorated throughout.The old boiler is in the utility room and I intend doing hte work myself as the boiler replacement is straitforward but I need help with adding whatever is needed to improve the efficiency of the system.My existing flue is in good condition but I have heard that a balanced flue may be better can anyone help please.

Hi AndyTow

One thing you WILL have to consider is that when an old system, such as yours, is upgraded then it will need to comply with the requirements of the CHeSS central heating system specifications. Matt would probably edit a link so just search on google for CHESS HEATING and you should find a link to the specs.

Basically, you will need to conver from your old partically pumped system to a fully pumped system, you will need to upgrade the controls on your system so that they provide full boiler inter-lock. What that means in English is that you will need to have;
A room thermostat (min 1)
Hot water cylinder thermostat
System controller with a min of 2 control zones, so that the HW and CH can be controlled independently and that the boiler does not operate when there is no demand for heat. This will inter-lock with your motorised valve or valves, depending upon which option you select (3-port or zone valves).

Plus, you are required to fit TRV's (Thermostatic Radiator Valves) on all rads except those in a room controlled by a room stat.

Plus, you will need to instal an automatic bypass valve between the boiler flow & return, after the pump but before the motorised valve(s).

Also - don't forget to insulate you house, it's easy to over look the requirements for insulation when talking about improving the efficency of heating systems.

Good luck, if you have any questions drop a line back via the site.

Cheers
Jim

PS You can also find out more about the Weekend Plumbing course and our CH & Wiring Controls course by following the link at the bottom of each project on this site.

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