Is My Vented System Working Properly?

[youdontwanttodoitlikethat]

Just moved to a bungalow. Its a conventional vented system, Concord WRS boiler, two 2-port motorised valves and 7 rads. Boiler stat set to 3.5 (max is 5)

When I turn on the heating which one of the two things below should happen?

A) The boiler should fire up, and stay fired up, until the room stat turns it off because the house is up to temperature.

B) The boiler should fire up, and after a while (5 to 10 mins.) cut out. It should then fire up again for a while. It will keep firing up for a while and then cutting out until the house is up to temperature.

The reason I ask, is that in my old house I had a combi, which would stay fired up all the way until the room stat was satisfied, not firing up and cutting out before temp. was reached. Which way should it be with this older system? I'm not saying there is a problem, perhaps that's how it should be. Takes a little longer to heat up than the combi system. Many thanks.

 

[adlplumbing]

could have air lock or problem with the pump and its cycling if keep turning self on and off

 

[youdontwanttodoitlikethat]

Thanks. So, you're saying its not right to keep firing and cutting out before room temp is reached? Basically, not enough water is flowing through the boiler to carry the heat away?

The pump was a little noisy until recently, and I'm not sure that it bled properly. See my other post -

//www.diynot.com/forums/viewtopic.php?t=233269

Could the pump be silted up?

 

[adlplumbing]

possibly but try bleeding your rads first if lot air in them this can all so cuase it

 

[twgas]

years ago boilers were often oversized so it may be heating up quicker than the system can cool teh system down, as such it would be working correctly, if the boiler is more accurately sized you may have a bit of a circulation problem.

 

[Boilerman2]

Are the radiators correctly sized for the rooms? are there TRV's on the rads in the room containing the Room stat, which are set lower than the room stat? it is not un-common for older boilers to cycle on/off whilst the house is heating up - you might like to increase the boiler stat, to say 4 or 4-1/2 as 3-1/2 is a tad low!!