Microbore warm radiator problem

[TonyTacT]

Hi All,
I have bought a house with an 8mm microbore system. I’ve checked under the floor boards and can see that the 4 downstairs radiators are run off a 22mm x 4 x 22mm manifold. But conservatory radiator is run off a 22mm x 10mm x 22mm T-joint on the flow side and the same back to the return, about 5 feet form the manifold. The 22mm pipes run more or less parallel in a loop. Initially the TRV value on the conservatory was stuck, so I gave it a gentle press and wiggle and got it to work to about 40%. Even turning off the all the radiators downstairs has little increase.
My question is the conservatory radiator is about 5 meters from the T’s. Will this have a big effect or should I look to change the manifold for a bigger one and connect the conservatory to that. Or should I change the conservatory valves and see if the problem lies there.
Any help is appreciated not only for me but so I can discuss it with a plumber should I get one. I added some fernox 400 cleaner a few days ago just to ensure the system is clean before making any changes.

PS. The boiler is only a few months old.

 

[dilalio]

shut down the other rads and see if you can push all flow into into the problem rad and get it fully hot. This may clear any blockages in that rad and valves. If it gets full heat, turn other rads back on one by one if it stays hot when all others are back open you have likely cleared some sludge. If not then tweak down the Lockshields on one or more of the other rads to 'balance' everything. If none of the above has an effect on the cool rad then you have blockages in that loop: rad/valves/pipe.

 

[TonyTacT]

Thanks for the reply dilalio. I have tried all the radiators off and it did get to about 70% but slowly. To me this would point towards a sludged up system? So I added the cleaner, which I will leave in for 4 weeks.
Can I ask, does the way the radiator is plumbed in sound ok. If I knew it was a plumber who chose to do it that way I wouldn’t question it. The problem is the previous owner was a right bodge it dodge it so I’m busy correcting all his ‘workmanship’ and getting the pro’s in where needed. (I know my limits)

 

[dilalio]

Water will take the path of least resistance, hence control and balance is achieved through the use of Lockshield valves. Is the pipework plastic? Where does it reduce down to 8mm? The T'ing off to the conservatory rad not being via the manifold should not be an issue as this is how you would add an additional 'leg' to a new rad on any system. I wouldn't leave the cleaner in for 4 weeks, a week at most should do, then drain down & eyeball the water coming out and dose again if you feel there is more gunk to come. Also when draining leave filling loop (combi) open to flush system through but keep an eye on pressure gauge.
If gravity system, leave F&E filling for a while to do same flush.

 

[TonyTacT]

The T that feeds the conservatory is plastic, it looks 10mm but possibly 12mm onto a 10mm copper elbow as it comes out of the wall. The rest of the system is all copper. I'll follow your advice regarding the cleaner and flushing. Very much appreciated.
I was going to fit Drayton 4 TRV valves as I’m planning to change all the old non convector radiators for convector ones. But I’m now thinking why bother with the TRV’s and just balance the system. Which should be ok?

 

[dilalio]

Good valves are an improvement, depends on how poorly existing ones are performing! But clean & balance the system first and see what results you get.

 

[TonyTacT]

Thanks once again for the advice its very much appreciated. I'll be giving it a try this weekend and hopefully get a good result. Have a great weekend.

 

[dilalio]

No problem.
Happy Easter

 

[Brigade77]

Microbore piping is derived from the very same veins & arteries that the Devil himself lacks to feed his non existent heart.

You'll need a very good, very honest plumber to spot where the blockage is constricting the flow . . . And there IS a blockage.

IME, rip the whole lot out & start again, you will ALWAYS have problems until you do.

 

[dilalio]

Microbore piping is derived from the very same veins & arteries that the Devil himself lacks to feed his non existent heart.

That doesn't make sense!
Oxymorons all over the place.
However, I do agree that mini and micro bore is a PITA and do not use it unless instructed to do so.

 

[Brigade77]

That doesn't make sense!
Oxymorons all over the place.
However, I do agree that mini and micro bore is a PITA and do not use it unless instructed to do so.

Yours makes no sense to me . . . until I pinch my nostrils together then repeat it out loud

 

[dilalio]

Good luck with your particular coping mechanism

 

[TonyTacT]

Hi All,
Microbore isn’t something I would ever have as a choice, but having said that it working perfectly apart from one radiator. So it seams a bit overkill to replace the whole lot for the sake of one radiator. Over the weekend I’ve drained the cleaner out and refilled and balanced. The result is that the conservatory radiator is now about 80% but slow to get to temperature.
I am now thinking or draining again but this time undo the lowest compression joint and let any rubbish out. The drain point is about 12 inches higher. Hoping that any rubbish in the system will come out there. Daft thinking or worth a try?
Once this is done the only options left, if it doesn’t work are to either install a 5 point manifold or replace with 15mm Hep20.
I do appreciate any help as I’m not plumber and perfectly happy to get one in if I know its what the pro’s recommend.

 

[ianmcd]

If it is easy enough to get to I would replace with 15mm Hep20 or any other brand for that matter, it wont be too expensive and at least you know it will work

 

[TonyTacT]

I think your right and a good long term messure. I think I will change the 10mm poly pipe to 15mm and see if that solves the problem. If it does, happy days if it doesnt, I think its a call te hpliber in job and hope they know their stuff.