Fraustrating ongoing problem help!!!

[SteveAle]

Firstly you guys on here helped sort my central heating super speedy the other month..you were brilliant in telling me it was a blocked cold feed!

I need to call on your services again! Only this time for my parents who have not had central heating for at least three weeks!!!!
This is three plumbers,two system flushes,and a brand new boiler fitted since!The quote below was written by my Dad this evening.

"Over recent years our 12 year old system that had a profile gas boiler has been inefficient In spite of regular maintenance. Radiators have failed to heat up at odd times in no particular order (although the two that seem to be furthest away from the boiler never get warm?). Various plumbers have tried solve the problem.replacing Pump,controller,3way valves and finally.the boiler with a Bosch condensing model Boiler.

The system now ,such as it is Still closes down and the house is extremely cold!!!!!"

Anyway Dad had a new boiler fitted on saturday as it appeared the metal heat exchanger was blocked.
Since fitted the radiators are still the same?? (a few heating up until warmish and staying that temp until they shut down generally twice a day.
Although when the boiler was fitted they shut off all rads and bled them individually and each singular rad was VERY hot!?!
But when all rads were turned back on the same problem occured as before.
And the plumber (who seems a good bloke) reckons there is so probably much sludge in the system thats probably causing the rads to not work,and has put in a strong cleaner to run in the system for the next two weeks.
I am no plumber obviously but does this sound correct?

Only other thing to add is that I asked dad what time the heating shuts down and maybe coincidence but it seems to happen when the water heating switches on?..does that help anyone to help me with a solution?
So tonight I turned the water off and heating constant and the rads seem to be staying on..only warmish on a few rads though?

Sorry this is so long to read but late this afternoon! I looked at the valve in the airing cupboard and the plumber had left it fully to the right (see pics below) in the MAN OPEN position
should it be in the AUTO position (fully to the left)?
I was thinking could this valve maybe not be fully operating to the heating side of the valve and staying mainly on the hot water side?you can hear it click when you turn from water constant to heating constant but the manual lever does not seem to move much?
I have moved t to the left anyway?

Sorry its such a long post but honestly its been going on for so long!! please can anyone help???? also I have added a pic below of the pipe work if it may help?

Steve

 

[NEALDEAN]

does indeed sound like sludge in the system, but have a look at your valves aswell for sticking pins / jumpers etc. check the pipework into the rads and see if one side is hot on the faulty rads.
if they look dated you may as well spend another few quid replacing them.

according to the picture the valve is set to auto anyway, this is correct.

what sort of flushes were carried out ?
were they just empty the system, refill it, then empty it again or were they chemical power flushes ?

Neal

 

[Gasguru]

Need more pictures, higher up and also the left with the cylinder. So far the pipework doesn't make sense. Who put that plastic fittings carp on there. That bypass valve doesn't comply either.

Did you get all the paperwork with the new boiler ie certificates etc as I think the installer is a cowboy - clearly with the system history he didn't see fit to check the system was clean before installing the new boiler.

The profile is was of the best boilers ever made - you can normally pump mud through them.

 

[SteveAle]

Thanks for the speedy reply Neal,
Before I left my parents this evening I put the lever back to MAN OPEN as he was the plumber and I was only guessing.
Regarding the flushes they were (at leat the last one) chemical flushes but not power flushes.
The flush they put in with the boiler is to be there for two weeks apparently?

 

[SteveAle]

Thanks for the reply gasguru,
will take a couple of shots tommorrow

Everyone in the know,why does every rad get very hot if all the others are shut down?
but when all on only a few nearest the boiler etc just get warmish?
In my unknowing opinion if a rad is blocked it just wont work full stop?

I thought maybe the blockage is so bad only a small amount of hot heating water is getting through to the (FEW) rads but when the water heating kicks in on the timer it takes preference over the heating it seems?
Is this correct?

 

[NEALDEAN]

i think with the system in such poor condition a proper power chemical flush with radiator vibration is in order. and dont forget to have him check the valves.

if you could send gasguru some more pics he will check out the pipework.

Neal

 

[bengasman]

First, make sure the dhw and ch are never on at the same time.
Shut that red valve underneath the mv for the moment and replace it later with an autromatic bypass. In the meantime make sure that the radiator in the room with the roomstat is always open by removing the plastic wheel head.
Finally, the hardest part to find out, is that you may have a loop. If you do, it must be cut.
You can find this out by somehow blocking off the flow to the cylinder, AFTER the 3way valve, let the system cool down, close all the rads and turn the ch on with the boiler stat on low and feel if the flow pipe gets hot near the first tee.
Sorry to say, but judging by the pics it looks like a bit of a botch job.