Only getting sporadic heat to 1-2 rads and only for a short time - confused!

Hi,

I hope one of you lovely people can help?

I have a new Ideal Logic Heat 15 condensing boiler with a new Honeywell actuator and a 17 year old Wilo Gold TF110 pump.

HOWEVER, the problem that I have started when the old boiler was there, so I doubt the new boiler is to blame.

The hot water works fine.

When the heating only is on, I only get heat to one upstairs rad (none downstairs) and then it slowly goes cold again about an hour later (with heating still being on).

As per various tips online, I've tried opening all lockshield valves to see if it helps, and also tried closing all but one lockshield valve, tried closing the upstairs ones only etc etc but to no avail.
If I completely turn off the one radiator that does work it makes no difference to any of the others.

Also, when I turn the hot water on, I get full heat to one upstairs and one downstairs rad for about half an hour but then they go cold soon after too. (Again, I've tried completely turning those ones off but there's no difference to any other rads).

They've all been bled too (there was no air in any of them anyway).

The pipes leading to the non working rads are completely cold too (if that helps diagnose anything?)

I am now lost as to what to do next!

All the rads have TRV's too (except the towel one in the en suite) and there's a room thermostat in the hall.

Any advice for this poor cold female will be much appreciated!

Thank you

Did the Ideal Logic housebasher just fit it and run away telling you it was your problem?

It was bought via one of these energy promotion Govt grants and installed last Wednesday, but I was away until this weekend so have only noticed the problem recently.

However, as I said, the problem was the same BEFORE this boiler was installed (that's partly why I went for a new one) so I'm doubtful as to the boiler being at fault, but then again, I am no expert.

Reading some other different posts, the pump gets very hot in use - am I right in thinking it shouldn't do this? Could it be the problem?

Any advice welcome please

If you're getting heat to some rads when hot water is called for, it would suggest your 3 port valve is stuck partially allowing some water through to rads.
(When your hot water is satisfied after the half hour you would then lose that heat to the rads.) Your
pump will be getting hotter than usual if its working against restricted flow, - it may even be kaput.
(I am not a qualified heating engineer, but as no one else has given you an answer as yet this may help. I'm sure if I am off the mark someone will soon chip in.)

We hear descriptions of some very odd situations.

Some are bad descriptions and others are good descriptions of odd situations.

It seems that in your case the rads may be wrongly plumbed to work with the hot water cylinder.

But as usual in this situation it seems you will need a competent heating engineer.

Tony