Just fitted K3 radaitor and the centre front panel won’t heat up

[Benny895]

Try closing it half way (the lockshield)

Hello Shaun I tried this heat got worse on the Radaitor. Any other ideas let me know

 

[ShaunCorbs]

Would say lack of flow through the rad is the issue

 

[John.g]

If the TRV isn't new maybe replace with new one or, temporarily, just fit another L/S valve to rule out any obstruction.
Also, even though indications are that the pump is performing OK based on the K2 rads heating up, would suggest purchasing a plug in energy monitor (~£15), stick a 3 pin plug on the end of the pump cable, plug it into a extension lead and monitor the power, this will give a very accurate measurement of the pump power from which the exact flowrate can be derived from the pump curves.

Is the 25kw boiler oil or gas and what make/model?.

 

[Benny895]

How long have you left it on as the only radiator for?

Whats your bypass set to?

Have you shut the motorised valve to the cylinder? If it's a Y plan have you turned the cylinder stat down to close the valve?

Are you on an open vented system or sealed?

Sounds like Air or pipe restriction/damaged. What size was the old rad?

If its air you can shut the TRV/lockshield off, open the air vent and wet vac or towel the water that comes out. Remove the air vent and connect a hose to it using a spare rad valve and some ptfe. Now open one end of the radiator one at a time full bore and run the hose to a bucket or drain, if you hear gurgling that's good news if not then its unlikely to be air.

If its a blockage try removing the rad, fitting a hose to each rad valve then a pressure testing pump as far back on the pipework as you can without going past a tee. pump it up until you're getting a nice flow out the end of the hose then repeat the other side.

If the TRV isn't new maybe replace with new one or, temporarily, just fit another L/S valve to rule out any obstruction.
Also, even though indications are that the pump is performing OK based on the K2 rads heating up, would suggest purchasing a plug in energy monitor (~£15), stick a 3 pin plug on the end of the pump cable, plug it into a extension lead and monitor the power, this will give a very accurate measurement of the pump power from which the exact flowrate can be derived from the pump curves.

Is the 25kw boiler oil or gas and what make/model?.

The boiler is an alpha 24r. I have been working on having another go at any airlocks in the system tonight as I work in the day. Heating system on and drainage out the front door

If the TRV isn't new maybe replace with new one or, temporarily, just fit another L/S valve to rule out any obstruction.
Also, even though indications are that the pump is performing OK based on the K2 rads heating up, would suggest purchasing a plug in energy monitor (~£15), stick a 3 pin plug on the end of the pump cable, plug it into a extension lead and monitor the power, this will give a very accurate measurement of the pump power from which the exact flowrate can be derived from the pump curves.

Is the 25kw boiler oil or gas and what make/model?.

The boiler is alpha 24r.

I have done some more testing and airlock freeing over the last couple of days. I have managed to clear the airlocks I think. I drained the water of the drain away Radaitor (and out the front door) and ran the heating system at the same time.Also when shutting down to the one radaitor.

The result is shut down all the radaitors and four down stairs radaitors open (3 of them the cast iron former lounge Radaitors) The Radaitor heats to a satisfactory standard. Both the in flow and outflow pipes are hot of the K3. Once I attempt to balance the system the K3 half heats.

What I’m thinking and I am going to do anyway because the house needs it; is the following. But this is a summer project. So won’t be immediate. In the former lounge it has three old cast iron double panel Radaitors, these can struggle to heat along with the K3 in similar manner (often only one struggling to heat) This room I’m going to change to one rad and get just as much heat but a type 22. Then get the other two removed and pipework tapped off. The hallway I have a cast iron rad which again I’m going to change (this is the drain away rad) to a type 22. Then I have two different bedrooms with cast iron rads. These I’m going to change for modern Radaitors one probably a type 22 and the other needs a single panel with fins.

This should create enough flow through the system by making it more efficient removing 2 rads and swapping the others for more efficient rads and probably slightly smaller as I’m swapping from imperial. I’m on 14 rads and 3 towel rails. My system should power 10-15 rads. Removing the (very old) cast iron (all) double panel rads and replacing them should make a difference.

What are your thoughts? Really interested of any opinions.

 

[ShaunCorbs]

Is it all off one 15mm drop or each on there own drop of 15mm off a 22mm

 

[Benny895]

Is it all off one 15mm drop or each on there own drop of 15mm off a 22mm

I honestly am unsure. The performance seems to match each other between the three in lounge and the K3. But I can’t be sure.

 

[Benny895]

I honestly am unsure. The performance seems to match each other between the three in lounge and the K3. But I can’t be sure.

But the other rads downstairs which there are three all seem to work great just the three in the former lounge and now the K3.

 

[Benny895]

The boiler is an alpha 24r. I have been working on having another go at any airlocks in the system tonight as I work in the day. Heating system on and drainage out the front door

The boiler is alpha 24r.

I have done some more testing and airlock freeing over the last couple of days. I have managed to clear the airlocks I think. I drained the water of the drain away Radaitor (and out the front door) and ran the heating system at the same time.Also when shutting down to the one radaitor.

The result is shut down all the radaitors and four down stairs radaitors open (3 of them the cast iron former lounge Radaitors) The Radaitor heats to a satisfactory standard. Both the in flow and outflow pipes are hot of the K3. Once I attempt to balance the system the K3 half heats.

What I’m thinking and I am going to do anyway because the house needs it; is the following. But this is a summer project. So won’t be immediate. In the former lounge it has three old cast iron double panel Radaitors, these can struggle to heat along with the K3 in similar manner (often only one struggling to heat) This room I’m going to change to one rad and get just as much heat but a type 22. Then get the other two removed and pipework tapped off. The hallway I have a cast iron rad which again I’m going to change (this is the drain away rad) to a type 22. Then I have two different bedrooms with cast iron rads. These I’m going to change for modern Radaitors one probably a type 22 and the other needs a single panel with fins.

This should create enough flow through the system by making it more efficient removing 2 rads and swapping the others for more efficient rads and probably slightly smaller as I’m swapping from imperial. I’m on 14 rads and 3 towel rails. My system should power 10-15 rads. Removing the (very old) cast iron (all) double panel rads and replacing them should make a difference.

What are your thoughts? Really interested of any opinions.

I should mention the 14 rads in total include 3 towel rails as rads

 

[John.g]

I had thought you had said that the K3s return temperature was only lukw warm even when on its own, the minimum output of your boiler is 6.5kw, if/when you run the K3 on its own does the boiler cycle on/off fairly rapidly, and same for other 3 in the former lounge if you just run those together.

 

[Benny895]

I had thought you had said that the K3s return temperature was only lukw warm even when on its own, the minimum output of your boiler is 6.5kw, if/when you run the K3 on its own does the boiler cycle on/off fairly rapidly, and same for other 3 in the former lounge if you just run those together.

When I just run the K3; the boiler stays on all the time. When running the boiler with the K3 and the 3 in the former lounge then it also doesn’t cycle and just stays in all the time. I haven’t ran the 3 in the lounge by themselves.

Initially when I ran the K3 by itself and the outflow to the K3 pipe was Luke warm, the boiler would cycle off and then back on.