Air lock i think

[scotthud]

All pipes apart.from.cold.feed from header are hot on the heating side in the cupboard

Some of the upstairs radiators are now starting to get a little warm? how long should it take to get hot? ive cranked heating up to full? or should i drain down and back fill again?

 

[scotthud]

ok so ive turned everything off and have started to drain the system again as mentioned previously, the ballcock dropped and then it started to fill the F&E tank back up, ive hung the ballcock up and turned the refill valve off and the F&E tank is draining down, ill give it another clean and backfill it again to see if it can free anything else

 

[Johntheo5]

Problems I'm afraid, the pump is set to max, ie LED III illuminated which is over 6M, even if pumping NIL, the power output should be 33W but its only indicating 14W so, either the pump is knackered or one of its inlet or outlet valves is closed or the pump is completely dry (unlikely), it's easy to check the inlet and outlet valves, these are located immediately below the pump and just above it, get a adjustable spanner or the like and turn the valve spindles, there should be 3 to 4 full turns between fully closed and fully opened, full opened is 3 to 4 turns anti clockwise from fully closed and vica versa.
When you have checked the valves fully open you might just change the mode by pressing the setting button until the 3rd LED on the right is illuminated, that mode is CP1 which is a constant 3M head, check the power W, if not reading at least 13W then no flow, should be reading ~ 18 to 20W, 0.6m3/hr, 10LPM, typical flowrate at a 3M head.

Depending on readings, above, the pump should be isolated by shutting the inlet and outlet isolating valves, the complete pump head can then be taken off by removing the 4 securing stud bolts and the pump ports and impeller inspected for sludge/scale etc.

EDIT: Just read your post and based on your findings then it points (now) more to pump problems which can fairly easily be identified as per above.

 

[scotthud]

ok ive just refilled and bled the rads again and turned on the CH & W ill go take a look at pump again. at present its on the III and 36w

 

[Johntheo5]

You are pumping ~ 2 to 2.5LPM, not a lot.

Just in case I'm looking at the wrong version of the Alpha2, when next its pumping showing 36W or near that, just shut the pump outlet (top) valve
briefly for about 5 secs or so and see and note if the power falls off, then re open it.

 

[scotthud]

Will do, at present all rads apart from 3 boiling hot and water slowly getting warm but I'd expect that with an immersion tank from cold(I hope)

 

[Johntheo5]

Very good, think you have a 36W pump but your test will soon confirm.

 

[scotthud]

How do I get the 3 rads hot that are stone cold even the flow and return pipes are cold, is it balancing them? They have been bled and are fine in that sense.

 

[terryplumb]

Try closing the hot rads down using their TRV ( if they are fitted) or the wheel head valve. Don't touch their lockshield valves.
Turning off the demand for hot water cylinder to be heated first.

 

[Ray1000]

Here is the (now) normal set up, its a VCP system, from the boiler flow pipe, you have Vent, Cold feed, (no more than 150mm from vent) and Pump,

Thank you for the explanation John,
Our system started 30 years ago fired by an Trianco TRG 45 Anthracite Boiler which was changed a few years later to an Ideal Classic in the garage, then an Ideal Logic in the loft in 2019 ... the pipework around the tank hasn't changed much since 1995.

 

[Johntheo5]

How do I get the 3 rads hot that are stone cold even the flow and return pipes are cold, is it balancing them? They have been bled and are fine in that sense.

I would first establish if the pump is performing properly by just shutting that outlet valve briefly as suggested, if the power falls to 20W or so then you know that the pump is working to its max capability of 35/36W and move on from there.

 

[Ray1000]

Scott, in case it is helpful for these people to know ... are the 3 radiators that are not getting hot downstairs or upstairs and not together in a separate part of the house ?

 

[scotthud]

Scott, in case it is helpful for these people to know ... are the 3 radiators that are not getting hot downstairs or upstairs and not together in a separate part of the house ?

all downstairs 2 in living room (front windows and middle of room) and one in kitchen, the living room is a through room to the dinning room and that radiator is fine, one other in kitchen is fine as are the two at the backdoor and downstairs toilet as is the one at bottom of stairs.

 

[Johntheo5]

Can you do that pump test and we can figure out then hopefully what the exact circulation flowrate is.

 

[scotthud]

Can you do that pump test and we can figure out then hopefully what the exact circulation flowrate is.

ok shut top valve power dropped down to 29/30w then when opened again i could here water flowing back into pump and its gone upto 35/36w again, one of the three radiators is now working, ive still got to finish closing the working ones off.

^^ 10 mins later^^

Shut all other radiators off the three cold ones now boiling hot, pump on III 36w and central heating only. Ill turn them all on now and wait for the schedule to kick in later around 16:30 and see whats what. (Fingers Crossed) wifes laughing as ive had to take jumper off as its getting warm in the house.