Boiler Puny or something else?

[rockguitar10]

Hi,

I have just replaced the valves on my radiators as 3 of the 6 were weeping causing slight loss of pressure.

Since then I have had the boiler engineer out (Halstead Ace High boiler) and he replaced the PRV and 'recharged' the expansion vessel.

We were still losing pressure but it went down to almost 0 overnight. I then discovered a leak in on of the replaced valves - it seems that the return pipe in one of the radiators was slightly thinner at the point where it was screwed into the valve and thus the olive failed to create the seal. Anyway, there was a lot of movement in that pipe so I cut around an inch off of the pipe to where it was at a regular diameter and replaced the olive - problem solved!

Or so I thought.......when the heating goes on in the morning (around 5am) the radiators upstairs are warm enough but the downstairs radiators are only luke-warm (at around 6:30am). Usually, if the heating has been on all day at the weekend the downstairs radiators are warm just after lunchtime and remain so until the heating is switched off.

All of the return valves are open fully and the downstairs TRV's are open fully.

Is my boiler too puny or could there be something else wrong?

I have bled the radiators and there isn't a temperature difference between the top or bottom of the radiators.

My living room is open plan but it's not just the room that is a bit cold - the radiators aren't particularly warm.

Any help appreciated.

 

[glasgowgas]

All of the return valves are open fully

try balancing system see FAQs and WIKI at top of page

 

[kevplumb]

All of the return valves are open fully and the downstairs TRV's are open fully.

there is your problem

try balancing the system

 

[rockguitar10]

Thanks guys. If i'm reading it right (and there's no guarantees!) this applies to radiators with only Lock Shield valves - 4 of my 6 radiators are 'double' radiators and are fitted with TRV's - is this still the way to go?

 

[TicklyT]

Yes - each radiator should have a lockshield valve at the opposite end to the TRV.

It's the job of the lockshield to stop all the heat going to one radiator by restricting the flow, leaving enough to share out to the other rads.

Just relying on the TRVs means the rads will probably only warm up one room at a time, as you've found out.

 

[D_Hailsham]

This pic shows a standard wheel head radiator valve. Removing the wheel head and replacing it with the cover on the right, turns it into a lockshield valve.

A radiator will have a lockshield at one end and either a wheel head or a TRV at the other end.

How to balance radiators