CH circulation issues

[Bailey1]

Hi Guys

I have a open vented 10 rad system in my 12 year old house, we moved in about 5 years ago and noticed in the 1st winter that the rads to the front of the house only got warm (rads to the back of the house red hot) the following winter front of the house dowstairs switched off would allow the front upstairs to work and vice versa. tried putting X800 through and although i got some black sludge through it never really solved the issue im at the point now where none of rads to the front of the house work at all, i have recently flushed the whole system again, removed every rad and flushed with hose pipe till running clear, i also attached my hose pipe to the feed valve and bled through until running clear and the same on the return valve (to every rad valve in the house) seemed to have a good flow when the hose pipe was attached. still no rads working at the front of the house (back of the house still red hot) pulled the floor up at the weekend looking for a non return valve in the 22mm pipe work but nothing, i have a mate is a qualified plumber and has helped me so far but im just after a second opinion, we are now thinking the air seperator might be restricting the flow (its also showing signs of being magnetic) im bound to have missed something out from this post so please any questions will be greatly appriciated and i will answer as best i can,

Thanks in advance!!!!!

Dave

 

[Bailey1]

Sorry just thought i best add that the return valves have bleed off points if i put a hose onto the bleed off on any of the non working rads and open the valves obviously there is now no restriction and the rad gets red hot instantly!!

 

[hammers4spanner]

tried balancing may have never been done properly

 

[Derek Hardman]

System needs balancing.

 

[Bailey1]

Guys thank you for the quick reply, what i have done is locked all the working rads off and left the non working rads open, the boiler tripped out and still nothing to the front of the house, would this still mean balancing??

 

[Rickster123]

How old is the pump?

 

[hammers4spanner]

what do you mean tripped out ??
are you meaning temp rose to quick in boiler and it shut down?
whats your current plumber done thus far

 

[Derek Hardman]

That would indicate blocked or airlocked pipe work, incorrect or weak pump if rads are furthest away.

 

[Bailey1]

APPlumbing the pump is approx 2 years old


Hammers4spanner i have glowworm ultimate boiler in the kitchen and yes basically the thermal cut out popped put (little red nib)

current plumber so far has assisted in the flush out, told me of the possibility of a non return valve, and now wanting to change the air seperator, all the flushing of the rads and the lines etc i have done off my own back

 

[Bailey1]

Derek the rads that are not working are the furthest away i am also starting to think of a restricted flow some where and a weak pump

 

[hammers4spanner]

put magnet on airjec should give indication if it has sludge moving through it ,

turn pump speed up possibly or check see you have airlock

 

[Bailey1]

another thing to add is my system does not have manifolds just 22mm feeds and returns with microbore coming off to feed the rads i have a picture of the pipe work under the floor if this helps i can post it

 

[Bailey1]

I have put a magnet on the air seperator and it does have a magnetic pull on it, the pump has the cap in the middle which has been bled with very little air coming out, pump has been on all 3 settings im afraid and nothing!!

 

[Derek Hardman]

Temperature tests along the pipework will give a better idea.

 

[Bailey1]

Sorry Derek do you mean the pipework under the floor or the pipe work on the rads??

 

[Derek Hardman]

Under the floor, your main circulation pipes, follow them along and you will locate the blockage.

 

[Richie_77]

Is it a micro bore system?
When you take off the rads at the front of the house do you get a flow through both of the rad valves? though this does not discount out poor connection in the first place, ie flow and return from and to the rad both connected to the same pipe.
Do you have a bypass which is wide open?
Personally id say its sludge and poor plumbing of the cold feed and vent.
Go hire yourself a power flusher, buy some fx2 and neutralizer. I recommend a fernox power flow mkIII. But at hundred liters and minute don't leave any open ends or your losing a ceiling

 

[diamondgas]

What size pipes supply the radiators, guessing microbore? Plastic maybe? Poor circulation is usually down to the pump or a restriction somewhere or other .. replace the pump eliminates the least expensive bit ... lots of temp tests you can do F&R but that's getting a bit techy!! 🙂

 

[Ollieg]

Can you isolate the side that works (gets hot) when you bleed off and bleed through the other side? This may back flush the blockage and start circulation.

 

[Bailey1]

Derek i will try this sometime this week and come back thanks

Richie it is a microbore system copper though not plastic, when the rads are off yes i can get a flow and according to my plumber mate a good flow, sorry not sure what you mean by by pass, my mate wants to power flush also.

Thanks Diamondgas (10mm) to the rads and they are copper.

 

[hammers4spanner]

dont rate power flushing myself rather just cut pipes out quicker and less hassle

 

[Bailey1]

Hi Ollieg i have tried back filling the sytem from the rear of the house (the working side) however i havent tried this on the front of ther house the side thats not working would this make a difference?

 

[diamondgas]

Thanks Diamondgas (10mm) to the rads and they are copper.

If you've flushed out all the pipework to the rads and the flow seems to be decent then I'd be going back to the pump or primary circulation pipework including the boiler .... Restricted circulation means that the extremities stay cold 🙂

 

[Bailey1]

The feed and return lines that are under the floor are 22mm and this where my mate wants to put the powerflush (although he has mentioned that he doesnt rate it either odd i know)

 

[Ollieg]

I think powerflushing is a good way to go.

 

[hammers4spanner]

i would go with diamond gas and you said that your airjec was drawing the magnet as well as boiler reaching temp quick and cutting out .
Has it ever pumped over?

 

[Bailey1]

Cheers Diamondgas it is doing my head in now because i have good circulation to the rear of the house (hot) i have good hot water i.e it heats up no bother so the flow around the hot water tank and back to the boiler seems ok i just cant seem to get it going to the front of the house, also good to mention that the 22mm feed under the floor comes to an equal T then goes to the rear and the front of the house, the same scenario is on the return line

 

[Bailey1]

Hammers4spanner if you mean from the airseperator up into the water tank in the loft then im sorry i dont know i have never checked to be honest but will do!!

 

[Bailey1]

Guys time is getting on and my dog has been scratting at my leg for the last 40mins wanting to go out :smiley2: can i just say thank you to all of you i never expected any replys as quick as this

Thank you for the advice, help and just shear interest you lot have shown i will take all of this and revert back

Thanks again guys

 

[diamondgas]

Cheers Diamondgas it is doing my head in now because i have good circulation to the rear of the house (hot) i have good hot water i.e it heats up no bother so the flow around the hot water tank and back to the boiler seems ok i just cant seem to get it going to the front of the house, also good to mention that the 22mm feed under the floor comes to an equal T then goes to the rear and the front of the house, the same scenario is on the return line

It tends to be the heating that shows up circulation issues and then it's commonly the furthest/droppers that suffer first. Unless you know circulation temp differences you can't say whether they are okay or not to be honest ... good circulation means even temp f&r circulation pipes... If one is a great deal hotter than the other then I'd be looking at restriction/pump problem... at a guess? You mentioned a potential place to focus on when you mentioned the airsep being 'magnetic' ... There or thereabouts may be where your restriction lies?

Just guessing to be honest, it takes 3D 1st hand knowledge to be more positive 🙂

 

[Bailey1]

Hi guys just a quick update! Removed the airjec not much in way of being blocked but full of black sludge, removed pump and isolation valves all clean so scraped the line that's feeds the airjec from the boiler and it was full of sludge, left the airjec out (just bypassed with new pipe work) and upstairs front rads are back on (mad hot) downstairs front rads getting a little but not what they should, my mate wants to remove the pipes feed and return to boiler and flush through, just g from there really but feel like I'm getting somewhere now!!! Cheers guys