New boiler - cold radiators

kittennose

FreeBear said:

kittennose said: Yes we had a flush. I had to open some lockshield valves the day after as some rads were not getting very hot while others were too hot to touch, these ranged from 45 - 55 degrees.

But now we have all 14 radiators very lukewarm, 25 degrees, not a single one is getting hot but clearly a tiny bit of warmth is getting into them but this isnt enough to even maintain temperature.

only a few radiators have old school trvs on and they look like the attached.

First pic is not a TRV, just a regular radiator valve that you can use to turn it off. The second pic is of a lockshield valve - This is the one you should be adjusting when balancing the radiators.

Get yourself a pair of cheap thermometer modules plus a couple of pipe clips. Shut off all the lockshields and open up the valves fully on the other end of the radiators. Fire the boiler up and give it 20 minutes or so to heat the water in the pipes. Starting with the radiator closest to the boiler, pop a thermometer on the inlet & outlet pipes. With a flow temperature of 60°C, you want to adjust the lockshield so that you get a temperature difference of 10-12°C. Open the lockshield very, very slowly, giving it about 5 mins between each tweak. The radiator will be slow to react, so don't go winding the lockshield fully open to start with.

Once you have done the first, move on the the next radiator and repeat, and so on for all the other radiators. After an hour or three, go back and check each one again.

Nearest radiator; we have one upstairs and one downstairs which are both about 6ft from the boiler (which itself is downstairs). Would we then go nearest to furthest on one floor before repeating on the other? I’ve a feeling upstairs is the first for some reason.

FreeBear

kittennose said:

FreeBear said:

kittennose said: Yes we had a flush. I had to open some lockshield valves the day after as some rads were not getting very hot while others were too hot to touch, these ranged from 45 - 55 degrees.

But now we have all 14 radiators very lukewarm, 25 degrees, not a single one is getting hot but clearly a tiny bit of warmth is getting into them but this isnt enough to even maintain temperature.

only a few radiators have old school trvs on and they look like the attached.

First pic is not a TRV, just a regular radiator valve that you can use to turn it off. The second pic is of a lockshield valve - This is the one you should be adjusting when balancing the radiators.

Get yourself a pair of cheap thermometer modules plus a couple of pipe clips. Shut off all the lockshields and open up the valves fully on the other end of the radiators. Fire the boiler up and give it 20 minutes or so to heat the water in the pipes. Starting with the radiator closest to the boiler, pop a thermometer on the inlet & outlet pipes. With a flow temperature of 60°C, you want to adjust the lockshield so that you get a temperature difference of 10-12°C. Open the lockshield very, very slowly, giving it about 5 mins between each tweak. The radiator will be slow to react, so don't go winding the lockshield fully open to start with.

Once you have done the first, move on the the next radiator and repeat, and so on for all the other radiators. After an hour or three, go back and check each one again.

Nearest radiator; we have one upstairs and one downstairs which are both about 6ft from the boiler (which itself is downstairs). Would we then go nearest to furthest on one floor before repeating on the other? I’ve a feeling upstairs is the first for some reason.

Start with the one nearest, work your way along to the one the furthest away.

In an ideal world, you'd run the heating and make a note of which radiators heated up first, second, third <yadda>, last. But life is too short for that,

ThisIsWeird

kittennose said:

ThisIsWeird said:

Kitten, which room has the Nest in it? Having a room stat like this is new to you? Silly Q - it's not that the room with the Nest is warm enough, and it turning off the Nest, and hence the rest of the house?
Q's: which room has the Nest?
What is the Nest set to?
Does the nest show both 'actual' room temp and 'target' room temps? If so, is the target higher than the actual? Give us some figures.

Nest is new but I am well used to modern thermostats coming from a hive. The Nest thermostat is in the landing and the target temp is 19 and the current temp is 16°. 

I have reset the nest and it still reads the same.

Note  can turn off the thermostat or reduce target temperature which will turn off the boiler so they are obviously communicating.

if I leave it set on our schedule (19°) or turn to any temperature above the current temperature the boiler kicks in and is running and making the right noises etc just not doing anything for the rads. 

Thank you - that's very clear, and you fully understand the control, so we can pretty much discount that as a cause.
FreeBear has described how to 'balance', and very likely that is the issue - in essence, the 'lockshield' valve on each rad (which is used to provide the correct amount of flow to that individual rad, and which depends on its size and distance from the boiler) will likely require being more open, but that needs doing in tweaks as described.
A quick test, tho'; you have thirteen lukewarm rads. Choose one, open its TRV/manual valve open fully, and open the other end - lockshield - two full turns. Does that rad now heat up fully?
(I notice you have microbore pipe, so just in case a dollop of sludge has been shifted which may be causing a blockage in the manifold, for example. Do you recall if they said anything about how dirty your system was? You have a magnetic filter fitted? Have you tried checking that to see if it's collected anything?)

kittennose

This is working! I had full heat to 1 radiator now slowly going through each doing half turn then bleeding and going on to the next. I am finding some previous rads in the chain are then going cooler as I open more so I assume I simply go back and open it a touch more?

I am finding these all need bleeding and they are letting out a lot of air - despite doing it twice yesterday and seeing no air issues. 

ThisIsWeird

kittennose said:

This is working! I had full heat to 1 radiator now slowly going through each doing half turn then bleeding and going on to the next. I am finding some previous rads in the chain are then going cooler as I open more so I assume I simply go back and open it a touch more?

I am finding these all need bleeding and they are letting out a lot of air - despite doing it twice yesterday and seeing no air issues. 

Ok, that's progress... :-)

Yes, you can arrive at a certain level of 'balance' by twiddling forever, but FreeBear's method is the correct way. Check YouTube too for info on this.

Ok, the air... You will get some air showing up for a while after a new system refill, from air dissolved in the water, but I wouldn't expect 'lots', and I wouldn't expect this from many rads. You also mentioned in your first post that you'd already bled the rads? Even these? And they are releasing 'lots' of air again? 

Before you continue with your version of balancing :-), bleed all the rads first. If you find they have 'lots' more air tomorrow, summat is amiss.

kittennose

ThisIsWeird said:

kittennose said:

This is working! I had full heat to 1 radiator now slowly going through each doing half turn then bleeding and going on to the next. I am finding some previous rads in the chain are then going cooler as I open more so I assume I simply go back and open it a touch more?

I am finding these all need bleeding and they are letting out a lot of air - despite doing it twice yesterday and seeing no air issues. 

Ok, that's progress... :-)

Yes, you can arrive at a certain level of 'balance' by twiddling forever, but FreeBear's method is the correct way. Check YouTube too for info on this.

Ok, the air... You will get some air showing up for a while after a new system refill, from air dissolved in the water, but I wouldn't expect 'lots', and I wouldn't expect this from many rads. You also mentioned in your first post that you'd already bled the rads? Even these? And they are releasing 'lots' of air again? 

Before you continue with your version of balancing :-), bleed all the rads first. If you find they have 'lots' more air tomorrow, summat is amiss.

I will pay someone to do it properly asap, I just needed to check if this was a boiler install issue or something I’m responsible for sorting. (And getting heat into the house was key 😂)

They spent all of 10 mins adjusting rads before finishing and whilst I think they could have been more thorough I am fine doing this; even thought it’s taken a couple
of hours out of my self-employed working day.

Downstairs not so much air but now seems more settled and all rads hot if not perfectly optimised for flow and return temps!

ThisIsWeird

You can buy a trigger thermometer for around £20, or even less. I used one to help me set up mil's UFH, and what a boon it was - 'click' and you had a temp reading.

The problem with getting someone in to do this balancing job is the time! Done properly, it'll take HOURS! Most of it sitting drinking tea...

You can do this

kittennose

Do you mean those laser guns?

FreeBear

kittennose said: I will pay someone to do it properly asap, I just needed to check if this was a boiler install issue or something I’m responsible for sorting.

Paying someone to balance the radiators properly will cost a small fortune. It takes a long time to do it effectively, and you don't need any expensive equipment. A pair of these - https://www.ebay.co.uk/itm/314509217221 - Buy three for the price of two (£6.42).

You will find that as you get close to the right setting on the lockshield, it will only need the slightest of tweaks to get "on target". Maybe as little as an eighth of a turn.

kittennose

OK you've convinced me - brought 3 
Is there any rule what the incoming temp should be - assuming a CH flow temp of 60