Condensing boiler advice

[industryspark]

Hi

Just moved into a new house and it has a condensing boiler system. The actual boiler is a Baxi in the kithchen with a flu to the outside and the water tank and expansion tank is upstairs in a seperate cupboard. I have a few questions regarding this system as there are certain things that dont seem to be fucnctioning correctly. I will be getting someone to look at the system but id love some opinions first so i am atleast informed.

1, When i set the water and heating to 'on' the radiators only get mildly warm for the first 45 minutes or so.......almost like the system is proritising the water tank. Is this how the system works??

2, Their is one radiator in the living room which only gets warm at the top, the bottom is cold. Bleeding the rad makes no difference. This radiator is probably the furthest away on the system if this makes a difference. Any idea's?

3, The system when set to 'off' on the controller for both water and heating will fire up the boiler every ten minutes or so for a minute before going back off. I haven't had chance to look at the manual yet but is this usual? i.e, some kind of frost protection etc?

Thanks for any interest.

 

[easyflow]

The fact its a condensing boiler won,t make no difference in the it heats water and heating.
I would say your system does need looking at in the way of sludge or blockages.

 

[petit_pablo]

Radiator system probably has poor circulation. What you describe is not normal. Why is another matter......

Cold rad will be related to the above.

It shouldn't be switching on and off as you've described. Likely culprit is a motorised valve at fault. Possibly linked to rad issue.

 

[stem]

When i set the water and heating to 'on' the radiators only get mildly warm for the first 45 minutes or so.....almost like the system is proritising the water tank. Is this how the system works??

Is it an old one pipe system? if so, that's about the going rate for heat up time. Is there a manual by-pass valve that has been opened up too much and effectively creating a short circuit so that much of the water flows through that instead of the radiators? There will only be a certain amount of flow produced by the pump, so it maybe the hot water is getting most of it. It is the easiest route for the water to take in comparison with the radiator circuit. Usually a balancing valve is fitted on the return from the hot water cylinder coil to restrict the flow and balance the system, if so is it open too much? And although fairly rare, as you suggest, some systems are designed to give the hot water priority.

The system when set to 'off' on the controller for both water and heating will fire up the boiler every ten minutes or so for a minute before going back off. I haven't had chance to look at the manual yet but is this usual? i.e, some kind of frost protection etc?

Maybe. Could also be a wiring fault, or a sticking motorised valve microswitch, assuming that you have one.