How to drain a central heating system

For both Combi boilers and F and E systems. A few tips on draining your heating system and refilling.
Saved some money on plumbers fees? Use the THANKS button.
Many thanks Al.

[bob]

Love this guy. Any plumbing stuff I do, I always seek this guy out.

[yoyo]

Great video Al. I learn such a lot from your videos - really clearly explained. Thanks

[eddiejohnson]

Good video, what if you have sludge in the system, using an old back boiler?

[addaplaster]

Thanks governor.
Great explanation great video as usual

[ianclark]

Thank you - you have made it sound so simple and logical to drain down my system whilst I change valves for a new radiator. I am even thinking about moving the pipes into a wall channel to avoid tiling around the pipes that currently project out of the floorboards.

[GT-wgfr]

Love this Guy hes made my plumbing jobs so easy with all the good advice. My next job is to change a radiator and valves. Thankyou!

[MarshallsMusic]

So why didn’t you use your siphon expertise to drain the toilet instead of a cup ?

[nikprenga]

Does this apply to gaz mains comby and oil comby?

[bikerchrisukk]

Nice one Al, I did mine (F&E) yesterday but watched your video anyway. Keep up the good work 👍

[williammorley]

Would be reallty grateful of a quick reply as I have my central heating system currently drained off. Im attempting to refill with X400 but I can't push my hose far enough into the radiator, and the X45 keeps spilling out onto the floor!?.

[ww]

Brilliant, thank you. I plan on draining my entire system and then to remove and flush all radiators. What is the best method of cleaning the small f&e tank? I could drain and clean it by hand, but is there a chemical I could use to dissolve the sludge and then siphon it out? Thank you!

[henrybyrd]

In my bungalow, all the rads are at the same level. Should I try to work out which is the furthest? Not as easy as it sounds when all the pipework is concealed. How about repressurising the system when refilling each rad when the boiler is in the loft?

[pistopit]

Another great video, thank you. Can I just switch of the water in a system by closing the valve on a filling loop?

[pieandpeas]

If only working on one radiator downstairs, wouldn't an option be to isolate the boiler/ header tank as explained here, then turn off both valves on every radiator apart from the one you intend working on and one upstairs to allow air in, drain the system as explained here, do the work on the downstairs radiator and refill as explained here too? Then turn on the lockshield valves by the number of turns you did to turn them off to ensure they are still balanced? Inhibitor would still be in the system and would save a lot of hanging around to drain and fill?

[tk]

What if the lowest rad is on the same level as all the other ones on the ground floor. I just have one drain valve to the rad fitted in the hallway.

[pullman]

Many thanks I’m learning fast your the best on u tube.

[RANDEEP]

Can I not connect the hose on the drain of valve on the combi boiler?

[markmurran]

Is it definitely the case you don't have to turn off the water to a combi boiler before draining a system and if so why? Everything I read online says to isolate water to the boiler or turn off at the stop clock. Want to safely drain system before having new rads installed. Please help!

[abzmalikify]

Great video as always. Very much appreciated. When draining the heating system do the radiator vavles need to be fully open as the locksheild vavle are balanced?

[aswe]

Bungalow combi boiler central heating flush/draining advice


Need some help with this!

System recently has added sentinel x400 which now needs to be drained out.

So my goal is to essentially flush the system rather than drain it.

But draining the combi boiler system is a problem. Its a bungalow, rads are drop fed.

Drain cock on boiler is 3 foot off ground. one rad has a pegler type drain valve, will that rad valve drain off the whole system?

Will continuously repressuring the boiler help force the water though until it runs clear and not damage the boiler? should i have the heating on when doing this?

cheers!