No hot water although central

[Keith1]

Hi, I am new to this forum and I am hoping that someone can help. I am having trouble with getting hot water. I have just replaced the 3 way valve because I had hot water but no central heating, now I have central heating without hot water. Boiler is 5 years old, hot water cylinder is 8 years old and the pump is around 5 years old. I have bled all the radiators and the valve next to the hot water cylinder, for some reason the radiator in the bathroom has been connected to the hot water system and has been for 20 plus years however it does need to be bled on a regular basis.

I have just checked the header tank and found that the water is warm and I guess the water is going backwards in the system! The cylinder works fine if I put the Emerson on, the pipes going into the cylinder are hot when the hot water is on and cold when both central heating and hot water are on at the same time. If hot water is only on, the pipe going into the cylinder is hot however the outlet pipe is cold and the water is only Luke warm. The only thing I can think of is that there might be a blockage somewhere? Help please!!

 

[lame plumber]

if you drained down the whole system then refilled it you probably have an airlock. did you ensure the 3 way valve was locked open to allow the cyl and ch pipework to fill together? if its an airlock in the cyl u could try crack the top of the coil nut to bleed it if your brave enough. alternatively drain it all down and fill from the bottom via a drain of cock and hose pushing the air upto the fe tank as it fills. also check you put the pump in the right way round.

your bath rad is so you can dry your towels in the summer and the rad will rot away due to all the fresh water going thro it.

 

[PlumbBobBob]

did you fit the 3-way round the right way? b towards the hot water cylinder.

 

[Keith1]

did you fit the 3-way round the right way? b towards the hot water cylinder.

Hi, yes have checked 3 way valve and fitted correctly. I had a 3 way valve replaced about 2 years ago (builder fitted a Towers) this had stopped working and is why I had replaced it. I did get the builder to add 3 isolation valves to make any future installation of a 3 way valve quite simple. I did not need to drain down the system.

As for the cylinder I have bled the valve that comes up to about midway next to the cylinder. Thanks for the explanations about the bathroom radiator, now I know why it needed replacing about 6 years ago (started leaking).

 

[Deleted member 32524]

Sounds like an air lock. Open vented systems are prone to it. Try putting mains pressure down the feed pipe with all valves open. or as suggested try back filling. may be blocked with sludge may need a powerflush.

 

[Keith1]

Sounds like an air lock. Open vented systems are prone to it. Try putting mains pressure down the feed pipe with all valves open. or as suggested try back filling. may be blocked with sludge may need a powerflush.

Yesterday I connected a hose to outside valve and flushed system until water came out of the header tank overflow pipe. Thought this would cure the problem? All seemed to work okay although water only Luke warm.

This morning I had heating on a couple radiators upstairs one which was hot the other warm! And no hot water. I flushed the system again because I had noticed that all the water had gone from the bathroom radiator, I could also hear air in the pipes which go to and from boiler and water pump.

Boiler cuts out because it thinks everything is at the correct temp!

 

[Keith1]

Yesterday I connected a hose to outside valve and flushed system until water came out of the header tank overflow pipe. Thought this would cure the problem? All seemed to work okay although water only Luke warm.

This morning I had heating on a couple radiators upstairs one which was hot the other warm! And no hot water. I flushed the system again because I had noticed that all the water had gone from the bathroom radiator, I could also hear air in the pipes which go to and from boiler and water pump.

Boiler cuts out because it thinks everything is at the correct temp!

Just turned off the only radiator that was full on and now finally getting hot radiators around the rest of the house, have not dared to try hot water because I need to get the house warm for when the family arrive home.

 

[Howsie]

your bath rad is so you can dry your towels in the summer and the rad will rot away due to all the fresh water going thro it.

Fresh water?

 

[Keith1]

Yes straight from the outside mains tap.

Just turned the hot water on, bathroom radiator heated up fine but cylinder did not, so turned off bathroom radiator. This made the hot water go into the cylinder however I noticed that the header tank overflow was pouring out water, checked tank and found warm water coming back up therefore switched off hot water and tried to turn heating back on however air back in pipes between boiler and water pump.

Boiler now won't start because of air system, reconnected outside hose to valve to flush air out of the system however did not work this time! Therefore back to no heating or hot water.

At the bottom of header tank there is a pipe which has a shut off valve, if I close this and stop the water going back up into the header will it cause damage or build up pressure somewhere that might be more of a problem?

 

[Deleted member 32524]

Try putting mains down the feed pipe you will hear air being pushed through the expansion pipe. Make sure valve/s is open for cylinder coil etc. Turn down pump if at three. You are bleeding rads from ground up?

Shut off valve that is the water main by the sounds. It should be attached to the float valve. That is where you hook on to get the mains water for the feed pipe in the F&E to hopefully get air out. If not main do not close it!!

Just be persistent, these can be a pain sometimes. If you cant get it phone a plumber/heating engineer.

 

[Keith1]

Hi, I managed to find a builder/plumber to come around and look at the set up of the central heating system. He has managed to set it up correctly for the heating however he said that I have an air lock in a pipe near the bottom of the hot water cylinder. The pipe is angled slightly upwards then goes down and into the bottom of the cylinder, He could not get the air out. He suggested that I buy a pipe freezing kit and install coupling coupler c/w drain off compression 22 mm and use this to remove the air from the high point of the pipe. Should I do this?

I am not switching the hot water on at the moment as heating more important, currently using the Emerson to supply our hot water.

 

[Deleted member 32524]

Good idea to have an air release point on these cylinders. Just drain it again these freeze kits dont give much time unless you can get a machine or you are quick or buy multi kits.

W

 

[Deleted member 32524]

?? why did plumber not do it for you.

 

[Keith1]

Thanks for your comments Duncan, I really appreciate them. Plumber came round late Friday and did not have enough time, however he did get the heating working as it should. Will attempt the freezing as should be quite quick in getting the compression fittings tightened up, real issue will be the speed I can cut out the section of pipe.