No hot water. Central heating working fine.

[fireball-7]

Newbie here, 2 nights ago stopped getting hot water. From what I can guess we have an indirect water cylinder that is filled with water from a tank in the loft. I think our 3 way valve is working OK as the pipe after that is very warm and i can here 'stuff' happening inside the cylinder. The top pipe on the right is red hot as normal, but the lower pipe on the right hand side is stone cold. what way is the water meant to flow here? top right going into cylinder, bottom right coming out and back down to boiler?

The bottom right pipe only gets warm to the left of the on/off valve, stone cold after that. So depending on the flow of water wheres the blockage likely to be, that on/off valve or inside the cylinder?

We have had longtime issues with our upstairs central heating not heating very well and I have an engineer coming out to fix that on Thursday, namely replacing the manifold in the upstairs hallway which we expect is full on sludge. downstairs circuit is fine. is it possible this sludge buildup has also now effected the pipe that is meant to be heating the cylinder?

checked the tank in the loft and its got plenty water in it. not attempted checking for an airlock yet( there is a vertical pipe on the right hand side that looks like that is the one to untight to check for/clear an airlock, an offshoot of the top pipe at the right ( the hot one) that goes into the cylinder.

pictures attached for clarify. we've had the 3 way valve thingie changed a few times already and from what i can see that is working fine( as the pipe after it gets very hot).

 

[justlead1]

Its more likely to be air, especially if a bit of water has been drained off over the last few days. Try turning off heating and pushing all through the coil. You can on occasions crack a joint with a spanner say the highest point on the flow as it enters the cylinder / coil.
Just in case check the water level again in the small cistern in loft (Vent & Header)
Tracing the temp around M/vale from cold by hand, this may give you a clue as to remedy.
Good Luck

 

[Simon F]

if you are having work done on Thursday then that will be the time to check this issue as well,
could be related to blockage and all part of the same issue. or air lock as said.
still could be issue with the valve or cylinder stat, programmer, lots of possibilities.

 

[fireball-7]

Thanks for the replies guys, I'll hold off till Thursday. Got maintenance contract but they are not the best ( the guy coming out on Thursday is via ratedpeople.com as my maintenance folk have not returned my calls to give me a date for the manifold repair even though I was willing to pay for it £360....)

 

[diamondgas]

Have a look in the small tank in the loft ... If the water is hot/warm or there's water coming out of the one that loops over the top when heating and/or water is on then that's a good indicator as to what to be checking next! Gunked up manifolds and poor circulation point to potential installation issues ... IMHO

 

[Kimou]

Manually open the 3 port, push the lever and hook into the little dog tooth, it's spring loaded so will return and be held there. Switch on the hot water and see if you get it flowing. If not then probably air lock or sludge. If you do then maybe valve or programmer.

 

[fireball-7]

Manually open the 3 port, push the lever and hook into the little dog tooth, it's spring loaded so will return and be held there. Switch on the hot water and see if you get it flowing. If not then probably air lock or sludge. If you do then maybe valve or programmer.

Hi

Turned off all radiator valves and heating off, left hot water on only but no difference. The bottom pipe is still cold up to the left of the valve, where it gets scolding hot. Blockage at that valve? This valve was off before I opened it again yesterday, wether the guy who visited on Saturday did that as part of the manifold testing I cent answer...

Tried over ride on the 3 port but no difference.

The nut for the airlock pipe, which is a 6 inch offshoot of the top pipe( this one is scorching) on the right of cylinder is rusted shut, I'm scared to overegg that one in case I bust it!

One for the pro on Thursdays I think, thanks for feedback guys.

 

[Kimou]

Why did you turn off all the rads? They need to be on.

 

[fireball-7]

Why did you turn off all the rads? They need to be on.

To generate more water pressure into cylinder. Guess not , lol