How long can you run your central heating with out an inhibitor in the water.
The reason I ask is that I am changing a radiator at the weekend, and in about 2 months changing another.
I will be cutting the pipes so the heating has to be drained, but it seems a waste of money to spend £15 on a liquid
only to do it again in 2 months time
Thanks in advance
It probably depends to some extent to the chemical composition of your tap water - but I wouldn't run for 2 months without inhibitor.
If your system is vented, why not catch the water you drain out, and put it back in the F&E tank when you're ready to go - rather than using virgin water? [If it's a pressurised system you can't really do that.]
Even if you're cutting pipes, you don't have the drain the *whole* system. If you turn off both valves on all the rads (making a note of lockshield positions so you can restore the balance) the rads will stay full. If you put bungs in the fill and vent pipes (again assuming a vented system), there's no need to empty the F&E tank - and you can break into the pipework without all that much water coming out. Obviously, you'll have to empty the rad which you're changing!
Actually you can.
I have a separate and totally isolated heating circuit for my workshop run via a plate heat exchanger on the main system and with its own separate pump. Since it is fed underground and might be off completely at times or in the event of failure, it is filled with a mixture of Fernox Alphi-11 inhibitor/antifreeze and water. To make absolutely sure that freezing won't happen, it is run at a concentration of 40% ensuring a freezing point of -22 degrees. This involves 4 x 5 litre containers of the stuff at about £15 a go, so, no I don't want to waste it.
My solution for this is twofold.
- First was to have strategically placed lever ball valves to isolate sections of the system.
- The second involves the use of a pump-up garden sprayer and some plumbing fittings. You can buy these sprayers (Hozelock etc) from DIY sheds for about £15 or less. THey have an 8mm tube on the lance. This is shortened and placed in one side of a compression coupler fitting. The other side goes via a length of tube and 15x8mm reducer to a washing machine type valve. THe system can be drained into containers in the usual way rather than run to waste. It is refilled by returning the water into the sprayer and hooking the rig up via a filling loop braided hose. The sprayer can comfortably achieve 2 bar and repressurise a system.
I have filed a copyright on this idea, like the radiator cleaning one, so royalties gladly accepted.
Brilliant - I shall file that for future reference.
Presumably the same solution could be used for putting inhibitor into a sealed system, if an equivalent volume of water is drained out first?
[Does the lance have an 8mm *metal* tube , onto which you can fit a normal 8mm compression fitting? So it's 8mm lance to 15mm copper tube to in-line washing machine tap - which has a 3/4" BSP thread onto which the braided filling loop hose is screwed. Is that correct?]** Ditto my device for draining a rad in a vented system by pumping air through the bleed hole, and pushing the water up into the F&E tank - but I'm not holding my breath for royalties!
Thanks
That's precisely what it does. It incorporates a schrader valve, so you can apply pressure with the valves closed and then crack open one of the valves. It has both 1/8" BSP and 2BA threads - so it can replace either a bleed assembly, or just the screw. [Picture at
Now that's neat...... How did you drill the hole and what is the material soldered into the back of the valve? How does it hold the bolt in place?
I need to drain the system as I do not know what type is in their a the the moment
and the merchant said you cannot mix the two types of inhibitor.
Hence the reason I need to drain
Thanks
It is a pressurised system
I need to drain the system as I do not know what type is in their a the the moment
and the merchant said you cannot mix the two types of inhibitor.
Hence the reason I need to drain
Thanks
(I'm noy very good with computers this early in the morning)
SNIP
Oh dear Andy, Can you prove dates etc.? Fernox have been selling these with a nozzle which screws into the air vent plug hole for about 15 years IIRC. Mind you even then they sold at about £25-00 plus vat.
The 2BA bolt is actually screwed into the end of the the Schrader valve (just a car tyre valve with all the rubber cut off) which extends right down to where you can see the 2BA thread. The guts of the Schrader don't extend as far down, so I was able to tap a 2BA thread in the bottom end of the body. The larger 1/8" BSP bit is just a 1/8 plug with a hole drilled through for the Schrader valve to pass through the middle - and the ring of solder holds it together and seals it. [In my previous house, the rads had bleed assemblies which were 1/8" BSP].
The 2BA bit started life as a 2BA bolt with a hex head. I used a pillar drill to drill through the centre of the head and on through the shank, and then cut the head off and loctited the whole thing into the end of the Schrader valve. [I've actually refined it a bit more since the photo was taken by filing a conical end on the 2BA bit - so that it seals better on the seat in the rad. Prior to that, I had to use PTFE tape round the threads, as in
I was told you need to drain and flush the system with fresh water a few times to make sure none of the old stuff was laying about.
You can change a radiator without draining if you turn off both valves. This only works if you don't have to change any pipework though.
Can you not change both the radiators at once?
Bob
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.