used X400 and X800 but still no joy to get 2 rads going

[jumbo]

Hi All,

Used Sentinel X800 in system for a 2 weeks and drained system and then refilled but 2 rads still refuse to get hot, then done the same process with X400 and still no joy, today I completely drained again took the 2 rads off the wall that refuse to get hot and connected the hose to them flushed out all the sludge which was quite a bit put back on the wall refilled the system and prayed, but still nothing !! Really is driving me nuts as British gas who I have a service and breakdown contract with refuse to now come out unless they power flush which is just over 1K which I just have not got.

When I feel the pipe where the pipe comes out of the wall and goes to the rad it's hot but only on the left of each rad, the right hand pipe at the rad is stone cold, so my thinking is that the microbore pipe in the walls (newish house) is block on the return flow which then means that the hot water is not flowing through the radiator. it can't be either of the rads as I know they are completely free of any blockages after hosing them for 20mins each


If I drain the system again take both rads off that are not working and then connect a hose pipe to the microbore pipe on the return side and blast mains pressure through would this clear the blockage ? OR am I just wasting my time ?

I've also installed a magnaclean which I empty each weeks since installing 6 weeks ago and each time the water is proper sludged up even though I've completely drained the system and refilled 3 times in the last 4 months. It is getting better but not to the point where I can get these 2 rads going even though I've used as stated X800 and X400.

I was going to try Fernox ds40 but I think this may be a waste of money and time as I've already used X800 +X400 as I don't think that the chemical is getting to where the blockage is in the 10mm microbore pipe. All other 15 rads are super hot with no cold spots.....

Any help/advice really appreciated as I'm getting to the point where I've tried everything and a power flush may be the only option....

 

[HERTS P&D]

Do a bucket test on the rad valves.

Andy

 

[Agile]

If you must use X800 then 1-2 two days is all that's needed.

But close the good rads to encourage the flow to the cold ones.

Have you done any balancing?

Tony

 

[jumbo]

yep done the balancing months ago before I started with all the X800 + X400 also had BG install a new more powerfull pump before they said no more unless I pay for a power flush.

As I'm typing this now I've closed the good rads to as you said encourage flow to the 2 not working, I've done this numerous times but no joy...As I said all that gets hot is the 3 inches of microbore pipe that comes out of the wall that goes to the left hand side of the rad, but rad stays stone cold and so does the microbore pipe on the right of both rads that go into the wall.

I'm wondering if I drain system again take both rads back off, and connect a hose pipe to microbore pipe that stays cold on the right and blast
mains water through would this free the blockage ?

 

[gigz]

It might work, first try to get water out of that valve (as said bucket test) if its totally blocked you could try blowing it out, but use short sharp bursts as opposed to just letting it go. I take it you have an open vented system, if its a fairly new system it may also be piped up wrong and sucking air in causing excess sludge build up. To use x800 you at least need to get some flow through the effected pipe. Have you looked into hireing a powerflusher and doing it yourself. BG £1000 is a proper rip off.

 

[alan333]

Does your system have a pump with a lever with three different settings? If so, try cranking it up a notch. Our house is a newish one too with microbore and we need the pump on setting two for the "cold" rads to get warm.

 

[jumbo]

Hi Gigz,

Thanks for the advice, when you say bucket test do you mean leave the heating running with the pump pushing water around the system and then slacken off the right hand side of the rad that is not getting hot and see if the water comes out ? Or is this completely wrong ?

I had a look at buying a power flush off ebay as they weren't that much compared to BG price and I've then got it for future use or flog it on once sorted, but as I only have a problem with 2 rads and all other 15 are red hot top to bottom I was hoping to get these 2 going without going down that road as it looked quite complicated to use.

 

[jumbo]

Hi alan333,

Yeh as I said BG installed a more powerfull brand new pump than what I had 4 weeks ago, and still no heat getting to those 2 rads, new pump is set to max to try and get any blockage free with the other rads turned to off to get max flow to affected rads.

 

[bazdaman]

Close the valve on affected rads, remove rads and then open the valves one at a time into a bucket whilst the system is full, if one dribbles out and one is forceful then you have found the blockage.

 

[jumbo]

So I close the one side with the lock shield and the other by keeping the TRV on and screwing to the closed position, remove the rad open the lock shield and if the water pi$$es out the its not that side, but if the right where I think the problem is I turn the TRV and if the water just trickles out then the block is on the side where the microbore does not get warm in the slightest ?

Do I do this with the central heating on with the pump pushing the water around ?

If that is the case then once again drain the system and connect the hose pipe to the blocked end and blast on full mains pressure ?

 

[gigz]

Turn heating/hw off (and the pump) take rad off and open valves, one will be blocked. Unblock it (good luck, sometimes nigh on impossible) then add x800 for a few days with the other rads off. What size pipe is it ?

 

[jumbo]

10mm microbore all sealed in the wall, only bit you can see is the 2-3" that comes out of the wall, guessing that the I/D on the microbore is only around 8mm so no big surprise that it's blocked with such a small inside diameter.

Your nigh on impossible does not fill me with confidence TBH but think you may be right with what I've tried so far to get them hot and with my limited DIY skills, biggest problem is if I pay someone to powerflush there is no guarantee that they are also going to get the 2 rads running, and I could be a few hundred notes down the drain, if the one rad wasn't the only one in the kitchen then I'd leave it as not working but in the winter it's going to be Baltic.

 

[Agile]

Many would be prepared to do the rad pipe unblock for a no-fix no-fee.

In my case for about £260 !

But that's just for unblocking them and does not include power fushing which would usually be about £350 for an independent.

 

[Richardthe3rd]

If it's a 10mm manifold system. It could well be blocked at the manifold? 15 radiator system is a bit large for a 10mm microbore system?

 

[gas112]

Just because the pipe is getting hot doesnt mean its not blocked it could just be trickling through it