Baxi Boiler Advice

Hi, I have recently moved into a property which has a Baxi Boiler. I do not believe it is a combi boiler. My question centres around whether my boiler is functioing as it should.

When the hot water switch (on the Honeywell controller (from where the timings for the central heating and hot water are set)) is activated, the pilot light in the boiler burns fully and heats the water up just fine. It is only when the hot water is switched on like this that the central heating will kick in. The central heating DOES NOT work independantly of the hot water and this is my concern.

With winter on the horizon I will be having the central heating on for hours and hours and therefore the hot water will be burning away for hours and hours. Does this sound correct i.e. if the central heating is on for say 5 hours that the flame in the boiler should be burning fully for 5 hours (and therefore be constantly heating the water for 5 hours)? Is there any way to make the central heating and water work independantly. I have read about zone valves? Can they be installed? Any advice would be greatly appreciated. Thank you.

Reply to
RBec
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Is it a back boiler behind a Baxi gas fire? If so, you should be able to run it with the CH on and the HW off if the programmer provides those options and is working properly. It would be helpful to know the type of boiler and the options on the programmer. Regarding " Does this sound correct i.e. if the central heating is on for say 5 hours that the flame in the boiler should be burning fully for 5 hours", once the room temperature reaches the thermostat setting the CH should switch off, then back on again when the room temperature falls to the thermostat setting. Do you have a thermostat? If so, is it working properly? Is it turned to the maximum temperature so that switch off can't happen?

Reply to
Codswallop

I have one and it's the same although I'm sure it's just the way it's been wired up i.e. it could be changed.

Reply to
adder1969

Reply to
RBec

It is possible that the programmer isn't wired up correctly, or it is faulty, or there is fault with the boiler. The next time you have the boiler serviced it would be worth having the programmer and boiler checked, and asking about installing a room thermostat unless you have thermostatic radiator valves.

Reply to
Codswallop

Sounds like you have a fairly old system that was popular for many years and the design pre-dates motorised valves.

If so, the only controls on the system will be the main temperature one on the boiler. The nice looking wall programmer is largely decoration and only turns the boiler on and off from its mechanical clock. It is not possible to have the HW OFF and the CH ON. The only options are HW ON or HW/CH ON.

As the programmer had the facility to turn on the HW or the CH but needed a motorised valve to do this, the handbook will refer to this function, which may not be present.

The ultimate luxury refinement to this system was the wall mounted room stat that actually controlled the pump and made the things works quite well.

Reply to
EricP

If it has a motorised valve but it's not wired correctly or malfunctioning it can be that although you should be able to get CH only the only way to get CH is with another feedback signal of CH+HW.

Reply to
adder1969

Regardless of what the controller claims to be able to do, a gravity HW and pumped CH system *cannot* provide independent operation of the two functions without additional equipment - the HW will always continue to be heated whenever the CH is on.

The best solution is to convert it to a fully-pumped Y-Plan or S-Plan system - requiring some pipework changes and the addition of one or two motorised zone valves. [See

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for the various 'plan' definitions].

An alternative which is almost as good - and a lot better than what you currently have - is to go for a C-Plan solution. This requires only one zone valve and a tank stat, and involves very little in the way of pipework mods. With this solution, you still have gravity HW but the gravity flow is turned off once the HW is hot enough. So this *does* provide independent control over HW and CH - together with a boiler interlock, which prevents the boiler from firing needlessly once both demands are satisfied.

Reply to
Roger Mills

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