Problems with my S plan Heating system - Microbore pipes etc

No Mick.

No combined feed and vent.

I just thought that maybe I should combine the old feed and vent into each other.

Maybe I am totally wrong here though.

The system goes as follows. Hopefully this makes sense. Thanks for the patience by the way

Old system (worked)

Out of boiler, into a radiator, into the next radiator, into the next radiator, into the next radiator, then up to the cylinder. Out of cylinder, round the upstairs rads and back down again.

Basically there was no DIRECT flow and return to cylinder only.

Plumber cut and tee'd the original flow and added in a direct one to the cylinder. Removed old flow from cylinder and capped it off.

Took new return into cylinder, ran back to boiler house and tee'd that in there. removed pipe that used to go from cylinder to the vent pipe. Capped it off.

Valve put on down at boiler to control flow into old rad flow pipes

Fitted valve at cylinder flow pipes.

Fitted stats, electrics etc to control it all.

Fitted auto air vent up at cylinder valve.

I think thats basically it.

What went wrong?
Sponsored Links
have you had a look at the F&E yet?

is the cylinder surprisingly hot?

what happens to the boiler and the pump if you close all the hot rads?

what's your answer to my q about air in the rads?
John, I am not in the house at present. No internet there :(

Unfortunately I have only looked at the items mentioned earlier.

When you say look at the feed and expansion, what do you mean?

Do you mean for me to climb up into the attic whilst the system is running?

I am sorry that I don't understand and for appearing so stupid. I just like to find out whats wrong, as the plumber who installed it does not appear to be that interested in fixing it and thinks that he has done everything correctly :(

If my room stat gets the house up to temp, then the boiler shuts down.

I seem to ALWAYS have air in the upstairs rads, and with loads of bleeding it never goes away. downstairs is fine.

I think that connecting a hose into the header tank and forcing some water through it might be a good plan. Would I be wrong?
Sponsored Links
if the pump is running, and there is an obstruction which prevents the hot flow circulating correctly, then it may escape through the vent pipe into the F&E

so if you look at it when it is running, you might see water gushing into the F&E from the vent pipe. This is important.

finding out is there is enough water pressure in the upstairs rads to force out the air is important

finding out if the upstairs rads fill up with air again, after you have bled it all out, is important.
is that because there is not enough water pressure to fill the upstairs rads and force the air out?

I am guessing that you are right John. This was my initial thought.

So do I go for the hose option and fill it from the top down with the hose to get higher water pressure?

The main thing that I want to work it out here as well is whether or not it is all set up correctly?

Is the plumbing etc correct?

Thanks again, Alan
Do you not actually have a cold feed into the system??? (from the bottom header tank into the system)
There is a cold feed into the system. I am just thinking that the gravity feed does not have enough pressure to force the air out
if the situation is as I guessed, you have a blockage.

to check, tie up the ball valve in the F&E and drain a gallon of water out of the drain-cock at the lowest radiator.

If the water level in the F&E does not drop by a gallon, you have a blockage. This is very common in old open-vent systems that have been drained. If this is the case, I am surprised that any experienced plumber did not spot it.

there is also a chance of an air lock

do the test, and the next bit will be fairly straightforward.

A photo of where the 15mm F&E pipe comes down and joins onto the main circulating pipe will be useful.
There should be enough pressure if the tank is in the loft, are you using the original cold feed as it may have a blockage,

Where does the cold feed enter the system and where does the vent come off the system??? this is important,

There are many issues with this system an you really should get in a pro to put it all right, if the same bloke who did the plumbing did the wiring then you def need that checking

As said before this system is potentially a danger - gate vales isolating boiler, no bypass etc.

Get someone round asap, i think thats as far as we can go with you, sorry to be a bit blunt but you dont just understand the advice that has or will be given to you. ta

I did the wiring. I am an electronics technician at work, so I think that is right.

I will be doing all the things that you have said to check it.

The only thing I want to know from you guys befor you sign off is where do I put the bypass that you mention?

Other than that, is the plumbing side of the system essentially correct?
I did the wiring. I am an electronics technician at work, so I think that is right.

You should really KNOW that is right,

Ok - convert to sealed system
move pump onto boiler flow
bypass after pump but before zone valve to return pipework
get rid of all those gate valves or at least remove the tops

That'll do to start.........

The gate valve are only there in case I need to do work. They are all open.

Taking the tops of is no problem.

Why would I want to convert to sealed system? What benefit would this bring me?

Can I keep it the way it is yet move the pump to the flow side?

I still don't fully grasp the bypass thing.

Bypass to where?

Thanks again for all the help


DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links