Re-balanced - Radiators clicking

[oldskoo1]

Decided to re-balance after putting in a new pump.

This 12 year old house has plenty of inconsistencies, the flow and return are randomly assigned on each radiator.

I am wondering why on the radiators where the TRV is on the return, why does the flow valve click? It is not a plasterboard heating up clicking, its inside the valve and it sounds like air potentially. Although no air can be bled.

And it happens on all radiators where the TRV is on the return. I simply balanced the flow valve in these cases but doing so produced this noise despite the target temperature drop being correct.

Any ideas what it is and how i should alleviate?


No matter how hard i try my sealed system has gritty noises going through the pump (i do live in a hard water area) and occasionally trickling water sounds in the boiler pipes. I have an AAV and it does work as it went nuts when i swapped the pump. I've checked upper rads for air.

 

[D_Hailsham]

Are the TRV's bi-directional? You can tell by the two arrows on the body which point to the two pipe connections.

When you say the "flow valve" clicks, are you talking about the lockshield valve at the opposite end to the TRV?

Which boiler (make and exact model) do you have?

 

[oldskoo1]

Hi yes they are bi-directional

It is indeed the lock-shield valve on the opposite end to the TRV, but the lock-shield valve is the one that gets hottest first and is the flow in. This is also where the noise is.

The boiler is an ideal classic FF380

I can only assume that this noise is due to tiny air bubbles forcing through the screwed down lock shield, these rads are some of the first in the loop and are balanced correctly. I assume the boiler is scaled up and producing gas bubbles from the scaling?

Just to let you know this boiler is 12 years old and was malfunctioning when we moved in 2-3 years ago. The flow and return were on the wrong way round and the PCB relays were broken and both kept the boiler short cycling, not getting anywhere near hot enough for god knows how long. I don't know what this lower temp would have done to the boiler internals.

If it is scale are we talking a few days of x800, or a few weeks of x400? I treated the system with x200 and x100 last year. This did quiet it down a bit, the boiler occasionally pops now but not often.

p.s. the CH works very well now since i sorted these issues out, no trouble with heating but i'm reminded every time the heating comes on there are still some issues to sort.

 

[D_Hailsham]

What speed setting is the pump on?

What temperature difference did you use when balancing the system?

How far open are the lockshield valves? (Max and Min)?

Make and model of TRVs?

 

[oldskoo1]

Pump speed 2 - grundfos 15-60

11c diff but a few maybe 4 out of 21 rads are up to 15c.

lock shield valves on the noisy ones are a 1/4 of a turn open

TRVs are Pegler Terrier II

 

[D_Hailsham]

Everything looks OK.

Did you remove the TRV heads while balancing the system?

You say the noisy rads are 1/4 turn open. What about the other rads?

How many rads on the system?

 

[oldskoo1]

Yes TRV's closing were removed form the equation when balancing

There is possibly 1 other radiator which is a double panel large which when i throttle down use to make a crackling noise, this does not have a TRV I can see if it still does it but didn't notice it yesterday.

The other rads lock shields are between a 1/4 and fully open. The difference on the ones with the TRV on the return is that i restricted flow going in to balance it.

However i do have a couple of non TRV rads where i balanced them then also restricted the flow as they don't need to be on much, for these 2, even with restricted flow, they do not crackle/click.

21 radiators in total. It took a while!

 

[D_Hailsham]

The other rads lock shields are between a 1/4 and fully open.

That's part of the problem. No rad needs to be fully open to balance it as the typical LS valves is fully open at 1 - 1 ½ turns.

The difference on the ones with the TRV on the return is that i restricted flow going in to balance it.

It doesn't matter if the LS valve is on the input or the output, it is still restricting the flow through the rad by the same amount (for the same opening).

What are you using to measure the temperatures?

 

[oldskoo1]

Sorry when i meant fully open i was thinking a 2-3 turns on the lock shield

Only the very last radiators are fully open, around 3 turns. I would say 80% of all the rads are below 1 turn. Most of them 1/4 and then the rest in this group 1/2 to 3/4 turn open.


I used an IR thermometer with pre installed black PVC tape on the inlet and outlet pipes beneath and physically part of the radiator. Not the pipes coming out of the wall.

 

[D_Hailsham]

2-3 turns on the lock shield

Is that 2 to 3 turns?

I used an IR thermometer with pre installed black PVC tape on the inlet and outlet pipes beneath and physically part of the radiator. Not the pipes coming out of the wall.

Not sure what you mean . Normally a valve comes with an adaptor which screws directly into the radiator. There is no inlet/outlet pipe.

Or do you have vertical designer rads?

The best place to measure is on the pipe connecting to the valve; i.e before valve on flow pipe and after valve on return.

Use of black tape is a good idea, but make sure the IR thermometer is very close to the tape.

Try this method for balancing:

1. Remove all TRV heads and set rad wheel valves to max open (anticlockwise)

2. Close lockshield (LS) valves (clockwise) then open by one-third (1/3) of a turn.

3.Turn on boiler and set the room thermostat to a high temperature so the heating doesn't keep going on and off.

4. Let everything heat up.

5. Measure the temperature of the flow and return pipe at the boiler.

6. Adjust pump speed so the difference is approx 11C

7. Measure the return pipe temperature of all radiators and write it down

8. Close very slightly (1/10th turn or less) the LS valves on the rads which have a higher return temp than the boiler;open slightly those with a return temp lower than the boiler.

9.This will affect all rads, so wait 5 minutes for the system to settle down.

10.Repeat 6 to 9 as required until the differential is approximately 11C at each rad and at the boiler.

Do not expect perfection, a differential of 9C to 13C is acceptable, provided all rads are within a couple of degrees of each other.

When all rads have been balanced, replace the TRV heads, set the boiler stat and room stat to the usual settings.

Set TRVs and Wheel valves to desired position.

 

[oldskoo1]

Cheers for the instructions I did a similar procedure but I did 1 floor at a time before checking all at the end. I'm pleased to achieve between 10-15c drop.

I was trying to explain I didnt use the pipe coming out the floor. I used the pipe going into the radiator on the radiator side of the valve. It's part of the radiator design.

Interesting observation tonight. Ch was pretty quiet. Some crackling in the pump and some rads but not too bad.

The crackle in the pump was much louder with hot water only. Pump speed at 3 made it worse. It's when I noticed that the cold water pipe going into he hw cylinder has a very minor leak. Loads of crusting and a tiny droplet of water coming out of the line around the end of the pipe. If this is leaking a droplet or so when hw is on I assume it can also suck in air? Could this then get stuck in the ch loop and boiler?

Pic here

Untitled

• oldskoo1
• 15 Oct 2014
• 1

 

[oldskoo1]

I haves video of the noise during hot water heating
http://youtu.be/esfK0fTFosc

The total install here

Untitled

• oldskoo1
• 15 Oct 2014
• 1

Untitled

• oldskoo1
• 15 Oct 2014
• 1

 

[D_Hailsham]

I haves video of the noise during hot water heating
http://youtu.be/esfK0fTFosc

The total install here

Untitled

• oldskoo1
• 15 Oct 2014
• 1

What's going on?

The pump in the video is a UPS2, but the pump in the pic is a Selectric.

 

[oldskoo1]

sorry the pic of everything is an old pic from around 2 weeks ago - i changed the pump since to the pic in the video!

 

[D_Hailsham]

sorry the pic of everything is an old pic from around 2 weeks ago - i changed the pump since to the pic in the video!

That's a relief! I thought I might be the victim of a wind-up.

Anyway.

When the system is well balanced, the pump speed is usually lower than a badly balanced system. That's one of the reasons I posted the balance routine, which has to be done with the pump on a fixed speed. When the balancing is satisfactory you could try setting the pump to the appropriate Proportional setting.

As for the HW cylinder, is there a valve on the return from cylinder to boiler? If so, this can be used to balance the cylinder to give an 11C drop.

If air is getting into the cylinder via the cold feed, it can only get into the primary circuit if there is a hole in the heating coil in the cylinder. This would show up by the water level rising in the boiler feed tank.