4 plumbers down still not sorted

[Paul not a plumber]

A little update. I tried using the cold water pressure to back flush it like mentioned above by Muggles.
This appears to have stopped the coughing and spluttering (thanks Muggles) and the pump is kicking in and for NOW its continuing to run but...
Im not convinced the hot water is coming out with quite as much pressure as before and when i turn the thermostatic control for the shower to max hot its hot but but no where near as hot as it should be. The hot from the basin tap feels noticeably hotter than pure hot water from the shower almost like some cold is getting mixed with it whether i like it or not.
One of the previous plumbers swapped out the cartridge in the thermostatic could this be causing the variance in hot-ness?

Once more, many thanks to all of you for your comments i really do appreciate them. Ive spent a small fortune on this over the last year in fees and parts so im determined to get this sorted and i can only do that with you guys, so thanks.

 

[Paul not a plumber]

Unfortunately it appears i may be back to square one.
The pump started spluttering last night and the cycle of stop starting kicked in.
So would this suggest that its a cold water feed issue given the back flush using the basin mixer tap sort of temporarily worked?
The gate valve is def fully open, there is plenty pressure if i disconnect a cold feed and open the valve.
So we plenty cold water coming through so does that just now leave the possibility of the vent pipe introducing some air some how?

 

[Gasguru]

Pull out the flange and see if it's blocked with scale etc.

 

[Hugh Jaleak]

As above, and check the cold feed to the cylinder. I'd check top end first, outlet from cistern clear, any sign of silt or other detritus in the bottom of the cistern. If all ok, ensure any valves fitted are fully open, (dont rely on handles turning, need to physically check its open), if that's ok, look at inlet to cylinder, I have found these badly scaled up where they enter the cylinder.

 

[DP]

My money is on the outlet/ vent.

 

[Paul not a plumber]

I will update as soon as i can get back and get in the loft. I will start at the top as that seems a sensible approach and check the feeder tank to see if any crap in the bottom of it near where it exits to feed the cylinder.
Thanks all

 

[Nige F]

I went to a house once with no cold to bath - looked in Cold Storage and found a pron mag sunken and blocking the outlet

 

[Paul not a plumber]

I hope it was a good one, you still got it !!

 

[HERTS P&D]

I was called to a house with a non flushing toilet, I found an 'erection spray' in the cistern. I showed the householder and she was soooo embarrassed, as it must of being her husbands.



Andy

 

[Nige F]

I hope it was a good one, you still got it !!

Nah - it was stuck together.

 

[Paul not a plumber]

Okay got up in the loft last night and both the larger water tanks up there (not sure why there are 2 large ones? The central heating header tank is located slightly different area and is obviously much smaller) were absolutely crystal clear, any exit pipe was about 5 inches off the bottom and totally clear. Very little sediment in the tanks, i was quite surprised how clean they both were.
Anyway that rules them out.
So thinking the pipe that comes down from them and into the cylinder is the next area to check. this pipe has the gate valve on and that was only fitted about 2 years ago when the bathrooms were refurbed and feels perfectly normal in operation and appears to work perfectly when i swapped the pump (thats causing the issues) over.
So i dont think its that. So from there do i check the flange? If so do i have to drain the cylinder or anything, before i try to get stuck in with my spanners?
Cheers all

 

[Gasguru]

Make sure the immersion etc is off.
I would suggest you tie up the float valve and open the hot/cold taps and drain the cisterns.
Then you can unscrew the gate valve front section and pull out the gate/spindle assembly to check that.
Unscrew the vertical hot pipe connection on the cylinder...there will be a little water so use a towel (I'm assuming your pipework doesn't loop over the roof to feed bathrooms etc).
Feed a small tube into the cylinder and syphon out sufficient water to allow you to unscrew the flange and inspect (fill a short length of hose with water....much easier that sucking the water through)
That will save draining the whole cylinder and keep sufficient weight in it to prevent is spinning when you unscrew the flange.

 

[Paul not a plumber]

Okay thanks for that i shall try that next, may be a day or two though until i have time. Will update the thread in any event.
Cheers