Draining central heating question

Albermarle

FreeBear said:

Albermarle said:

ThisIsWeird said:

Albermarle said:

ThisIsWeird said:

Make and model of boiler, Nuggy? 
Turn the boiler output controls to off, any timer/programmer controls ditto, then it should be ok to power it up to view the pressure.
The filling loop is usually (should be) connected to the CH return pipe to the boiler, so if you fancy trying FreeBear's 'flush' method, you may need to ensure the draincock is on the 'flow', or else your flush could bypass most of your rads. A flush like this will also rely on having a decent flow getting through each rad, but some lockshields could be barely open a crack, so unless you are prepared to mess about with these as well, your draindown method might be best.
If you don't already have one fitted, consider adding a magnetic filter since your system will be drained down.

I do not have one of these, and as far as I can remember, nothing has been added to the system ( inhibitor etc ) for at least 7 years. Heating/boiler ( serviced every 18 months or so) all run without problems.
I wonder how necessary all these items are, or whether I have just been lucky.

Yeah, you got 'lucky' written all over you, pal.

The Mag Filter is a good-to-have, but inhibitor, pretty much essential.

If Nuggy has concerns about sludge in their system, then fitting one will continue to capture most of whatever remains as it flies around, after they've done the 'flush'.

I am going to Screwfix on Monday !

Screwfix and Toolstation are both open until 16:00 on a Sunday.

This little device looks to be useful for dosing a sealed heating system ->

Worth shopping around as the price does vary wildly (from £8 up to £30).

According to Youtube videos, the easiest way is to top up a Towel rail radiator ( which we have) . As the bleed screw/nut is on the top, you can just pour in the inhibitor without needing a special device like above.
Procedure is turn off TRV and lockshield valve.
Open bleed screw
Loosen connection above either the TRV or lockshield valve, until water leaks out.
After losing about a litre tighten up again
Remove bleed nut.
Top up with inhibitor.
Replace bleed nut
Open TRV and lockshield valve
Turn on heating
Bleed any air out of radiator.

Does that sound OK ? It looks simple enough.

Main issue seems to be collecting the water as it leaks out.

FreeBear

Albermarle said:

FreeBear said:

Albermarle said:

ThisIsWeird said:

Albermarle said:

ThisIsWeird said:

Make and model of boiler, Nuggy? 
Turn the boiler output controls to off, any timer/programmer controls ditto, then it should be ok to power it up to view the pressure.
The filling loop is usually (should be) connected to the CH return pipe to the boiler, so if you fancy trying FreeBear's 'flush' method, you may need to ensure the draincock is on the 'flow', or else your flush could bypass most of your rads. A flush like this will also rely on having a decent flow getting through each rad, but some lockshields could be barely open a crack, so unless you are prepared to mess about with these as well, your draindown method might be best.
If you don't already have one fitted, consider adding a magnetic filter since your system will be drained down.

I do not have one of these, and as far as I can remember, nothing has been added to the system ( inhibitor etc ) for at least 7 years. Heating/boiler ( serviced every 18 months or so) all run without problems.
I wonder how necessary all these items are, or whether I have just been lucky.

Yeah, you got 'lucky' written all over you, pal.

The Mag Filter is a good-to-have, but inhibitor, pretty much essential.

If Nuggy has concerns about sludge in their system, then fitting one will continue to capture most of whatever remains as it flies around, after they've done the 'flush'.

I am going to Screwfix on Monday !

Screwfix and Toolstation are both open until 16:00 on a Sunday.

This little device looks to be useful for dosing a sealed heating system ->

Worth shopping around as the price does vary wildly (from £8 up to £30).

According to Youtube videos, the easiest way is to top up a Towel rail radiator ( which we have) . As the bleed screw/nut is on the top, you can just pour in the inhibitor without needing a special device like above.
Procedure is turn off TRV and lockshield valve.
Open bleed screw
Loosen connection above either the TRV or lockshield valve, until water leaks out.
After losing about a litre tighten up again
Remove bleed nut.
Top up with inhibitor.
Replace bleed nut
Open TRV and lockshield valve
Turn on heating
Bleed any air out of radiator.

Does that sound OK ? It looks simple enough.

Main issue seems to be collecting the water as it leaks out.

If you have a towel radiator with the blanking plugs pointing straight up, the above process sounds reasonable - Wrap a rag around the nut you loosen off, and the water won't spray everywhere. Or use one of the drain down points elsewhere on the system.

If you are messing with the lockshield valves, make sure to mark the position before shutting it off. Alternatively, use a pair of thermometers so that you can reset to the appropriate temperature drop.