It's all in the installation manual, which you should have.
That's where they went wrong. You should remove the valve head so the valve is fully open.
I'm not surprised.
Bypass Valve still flowing when fully wound down
- Thread starter ChrisNason
- Start date
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Do the bucket test test with the system OFF and from each side in turn roughly measuring how long it takes to say half fill the bucket or any other easy to judge amount.
Its important to start with the boiler pressurised to the same value of say 1.5 Bar. Repressurise after testing the first valve before starting on the second.
The flow in that test is provided by the charge in the expansion vessel and will only run for a few seconds and provide a few litres.
The objective is to see how fast the water comes out at first. There should be a good flow of perhaps 1 litre every five seconds.
Remember at the start there will be 1.5 Bar pressure so the flow can be fairly high.
Tony
Its important to start with the boiler pressurised to the same value of say 1.5 Bar. Repressurise after testing the first valve before starting on the second.
The flow in that test is provided by the charge in the expansion vessel and will only run for a few seconds and provide a few litres.
The objective is to see how fast the water comes out at first. There should be a good flow of perhaps 1 litre every five seconds.
Remember at the start there will be 1.5 Bar pressure so the flow can be fairly high.
Tony
Agile
Mostly OK. But it's not a system boiler. Just an open vent classic set up. I'll run it with everything off and see what I get.
Any thoughts on the ABV staying hot?
D_Hailsham
I didn't see them actually doing the balancing but at the start they put the caps on (perhaps to stop the flow while taking out the radiators)
I don't think they were cowboys. At least they had a recommendation.
Mostly OK. But it's not a system boiler. Just an open vent classic set up. I'll run it with everything off and see what I get.
Any thoughts on the ABV staying hot?
D_Hailsham
I didn't see them actually doing the balancing but at the start they put the caps on (perhaps to stop the flow while taking out the radiators)
I don't think they were cowboys. At least they had a recommendation.
Sorry then if its an open vented system its easier to manage as the pressure will be lower and you will have less water to splash about.
In that case expect about 3-4 litres per minute but the exact amount depends on the system design and available heard of water.
As the water comes out look for any dirty bits being washed out.
The caps were probably being put on the rads valves to close them off when removing rads.
Tony
In that case expect about 3-4 litres per minute but the exact amount depends on the system design and available heard of water.
As the water comes out look for any dirty bits being washed out.
The caps were probably being put on the rads valves to close them off when removing rads.
Tony
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There is always the possibility that a bit of dirt is stopping the valve from closing completely. Unfortunately, the only way of checking this is to remove the valve.
I didn't realize that the rads had been removed, so that is a possibility.
Did you notice if the heads were replaced before the balancing was done?
What happens if you close all rads except the problematic one? Does it now get hot?
Right... First test
D0 shows it set to 14kW
The 428, as bought, was 28kW. (The 418 is 18 and the smallest 415 is 15 - easy really)
Now for the temp measures, but I need some flow first.
D0 shows it set to 14kW
The 428, as bought, was 28kW. (The 418 is 18 and the smallest 415 is 15 - easy really)
Now for the temp measures, but I need some flow first.
Next test.
Open up 3 rads fully and set room thermostat up.
Back to Boiler and find the flame symbol is alight but it's silent.
d40 says 53c; d41 says 43c
After 2 minutes the traditional boiler sound starts and d40 rises steadily to 67c while d41 still says 43c
Boiler stays at this sound for 4 minutes and d40 67c. eventually d41 rises to 45c.
But this is the first time for ages I've had a steady boiler sound and sustained running
Open up 3 rads fully and set room thermostat up.
Back to Boiler and find the flame symbol is alight but it's silent.
d40 says 53c; d41 says 43c
After 2 minutes the traditional boiler sound starts and d40 rises steadily to 67c while d41 still says 43c
Boiler stays at this sound for 4 minutes and d40 67c. eventually d41 rises to 45c.
But this is the first time for ages I've had a steady boiler sound and sustained running
That has been achieved because the boiler power has been reduced to 14 kW ( You said it was 18 kW though. ).
However down rating the boiler does not solve the flow problems.
You still have not done the bucket test or the all rads off except the bad one.
You seem to be very selective with what you are prepared to do.
Tony
However down rating the boiler does not solve the flow problems.
You still have not done the bucket test or the all rads off except the bad one.
You seem to be very selective with what you are prepared to do.
Tony
Now for the silly update.
In order to get the boiler working I opened up 3 radiators fully. The bathroom TRV. The hall (that was virtually closed) and the rear bedroom (above the faulty radiator and previously wound down a lot)
All 3 are stonking hot. But the faulty radiator is now warm all over? Not as hot as the others but a very reasonable temperature.
The ABV is still as hot as before so an awful lot of water is passing through it.
Views?
In order to get the boiler working I opened up 3 radiators fully. The bathroom TRV. The hall (that was virtually closed) and the rear bedroom (above the faulty radiator and previously wound down a lot)
All 3 are stonking hot. But the faulty radiator is now warm all over? Not as hot as the others but a very reasonable temperature.
The ABV is still as hot as before so an awful lot of water is passing through it.
Views?
And Agile
I'm not ignoring your advice. Just doing the easy stuff first. So far I haven't opened up the loft or got anything wet. I'll be doing that at the weekend.
ps. I'm also very slow (I couldn't make a living from this). The next test is all the radiators off except the poor one. (my wife has just commented on the warmth now in the house but said it's because we have no wind this evening so she's not impressed!)
I'm not ignoring your advice. Just doing the easy stuff first. So far I haven't opened up the loft or got anything wet. I'll be doing that at the weekend.
ps. I'm also very slow (I couldn't make a living from this). The next test is all the radiators off except the poor one. (my wife has just commented on the warmth now in the house but said it's because we have no wind this evening so she's not impressed!)
Perplexed again
I had good flow last night. Of the 3 radiators that I put to max I had to turn down the one in the back bedroom (above the faulty one) to reduce the temperature for sleeping.
This morning, the faulty radiator was very cool again.
It seems the boiler was back to short bursts. Opening the bedroom again restored the boiler to longer bursts and then got the faulty radiator running.
More tests tonight. (including everything off except the faulty one)
I had good flow last night. Of the 3 radiators that I put to max I had to turn down the one in the back bedroom (above the faulty one) to reduce the temperature for sleeping.
This morning, the faulty radiator was very cool again.
It seems the boiler was back to short bursts. Opening the bedroom again restored the boiler to longer bursts and then got the faulty radiator running.
More tests tonight. (including everything off except the faulty one)
Now compare that to the total of your rads using Stelrad Elite Catalogue to see if they are similar.
The flow temperature is probably set to 67C. Is the temperature control on the front of the boiler set to max or something lower?
At 14kW output the max flow rate should be 10 litres/min (0.6m³/hr; 0.17 litres/sec. Depending on which speed you have the pump set to, the head will vary from about 3m to 5m. This is well within the range of your ABV.
Agile
This part of the CH is on one of the only existing bits of pipework. We had the Dining Room/Kitchen knocked through so had to remove a large old panel radiator (to allow the wall to be removed. This new Column Radiator is connected to the shorter pipes. Ironically, this old panel was the warmest in the house. So the relationship of the pipes at the rear of the house is the same with just 2 bedrooms above and this drop coming off the middle of the linking pipes.
I can be fairly confident that there was no linking of performance when it was the original panel.
I shall do the test tonight to see if this new column works with everything else off.
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