Central Heating Inhibiter

[RunAwayHorse]

Hi all.........I have recently part drained down our system so that I could add Sentinel X200 as a means to minimising boiler noise etc. Having added new water, I have read hat a water inhibiter such as X100 is also a good measure to help prevent corrosion etc.

As the F&E tank is half "full", would I need to drain down again to add the inhibiter, or can i just pour it into the F&E?

I don't want to lose the X200 that i have put in the system by draining off again, but I think I read somewhere that placing into what would become a full an F&E tank, would prevent the inhibiter from getting into the sytem for a long time.

Can someone, therefore, please advise me, as to the best course of action.

Many thanks in advance.......Regards..Peter

 

[bathjobby]

It will go nowhere if you just pour it into the F&E tank. Just drain enough off to empty the tank and the connecting pipework i.e. the amount in the tank plus a few gallons, pour it in and refill (may have to bleed top rads).
N.B. if your F&E tank is half full, thats too much. you only need the water level in there just high enough to completely cover the feed pipe at the bottom of the tank, so when you refill, adjust the ballcock accordingly. Higher water levels aren't needed and it just means that the water level in the expansion pipe is also nearer to the top (same level as tank under gravity) and therefore will take less expansion before it pumps over in to tank = condensation, dripping overflow pipe and worst still as the water pumps over it re-oxygenates rendering your additives (at least the one that takes out oxygen to inhibit corrosion) useless.

 

[RunAwayHorse]

Thanks bathjobby .....your information and advice is extremely enlightening and very much appreciated.

A query that I have, following reading your comments, is that the F&E tank in our loft is quite a sizeable one, though not as big as the one next to it for the domestic hot water system - but not a small tank as you often read about probably about 15 plus years old ?

The F&E is traditional in other senses eg ballcock float - hot water overflow pipe bending over the top of the tank and an overflow outlet pipe which is sited near to the top of the tank.

The fill hole for the c/h system is on the very bottom floor of the tank - not sure if that is the norm. So where you say just cover the opening with water etc, and adjust the float accordingly. I cannot really do that as the float (being near the top of the tank) could not be adjusted that much as the tank will be probably a quarter /one third full, before it touches and lifts the float?

Any further advice / comments, that you might have on that would be very helpful.

One last point if I may, when you say draw off a further couple of galls from the sytem to alow the inhibiter to enter etc, as we have 12 rads over the whole house + basement (mostly doubles) - given the size of our F&E would we be losing most of the new X200 out of the system and be replacing it with the untreated water from the F&E?.

Thanks a mill'...........Regards..Pete

 

[bathjobby]

F&E tanks are normally quiet small around 16" cubed or so, so it sounds like someone has used an 'odd' size tank in your case. If your system is not pumping over (water flowing / dripping out of the expansion pipe) I wouldn't be concerned but would just adjust the ballcock as low as it will still function properly.
On the x200 loss, get you hand in your pocket and buy some more

 

[RunAwayHorse]

Thanks bathjobby.........LOL............you have been very helpful with your info

No dripping into tank or overflowing .so looks like all is well as you say ....except got to repurchase more X200 LOL.....

By the way can i put both in to the tank together then ?

Al the best ........Pete

 

[slippyr4]

Thanks bathjobby.........LOL............you have been very helpful with your info

No dripping into tank or overflowing .so looks like all is well as you say ....except got to repurchase more X200 LOL.....

By the way can i put both in to the tank together then ?

Al the best ........Pete

Yes they can go in together.

 

[RunAwayHorse]

Thanks Slippey.much appreciated........Regards.......Pete

 

[ricarbo]

I'd change the F & E tank they cost less than £10. Because it's wrongly fitted. The outlet should be about 25mm above the bottom. i.e. on the side. This is so the rubbish doesn't go down the pipe. it should also have a tight fitting lid, a dip tube to stop air coming up the overflow and freezing the water (that is to say the overflow pipe turns down inside the tank and this downward facing pipe should be below the normal surface level of the water). And a vent on top to let air in and out, but not insects. 22 mm 'Expansion' pipe enters lid through gasket. Does yours have all this?