Bath only 1/4 filling with hot water

sumosi

Can someone kindly advise - My hot water for my bath is only filling up 1/4 it then goes cold then no water at all so only getting full just over a quarter.

Calahonda52

we need a bit more information about the setup: impossible to advise on above detail.
House or apt
how many floors
where is water tank in relation to bath
heating systems
hot water cylinder or combi gas boiler or immersion.
pumped or gravity fed
How big is bath
etc

sumosi

Thanks Calahonda52
It is a two story house with a Combo boiler
I have a cold water tank in my loft (roof) and a hot water tank on the top floor of the house is my airing cupboard, which is a gravity-fed system.
Bath is the standard size (1700mm in length and 700mm wide) which is downstairs directly under the airing cupboard
Cheers

Calahonda52

Thanks.
So what about water in the rest of the bathroom, as well as hot tap in kitchen.
[Cold tap in kitchen is from mains so not relevant for now]
Does the bath water eventually come back or what do you have to do the get it back.

By Combi I meant that you have no hot water cylinder so we can rule that out

sumosi

Ok so all the hot water taps in the house are depleted , do not provide water until about 1 hour + later when back to the normal set up.
Thank you

Calahonda52

Thanks: so no hot or cold water in the bathroom for a hour, not just no hot?

Okay, I am no expert here but by my asking some of the right questions will make it easier for the experts.

Sounds like there is a blockage or an airlock somewhere in the system.

have you safe access to the attic tank?

there is a pipe from the top of the hot water cylinder up into the attic and it loops back over the cold water tank: this may have come partially blocked.
Likewise could be a piece of wet insulation in the bottom of the cold water tank, blocking the flow from the tank.
There are normally two pipes out, one to the bottom of the hot water cylinder, the other for all the other cold except kitchen.
Is it covered?
What age is house?

Is hot water tank well insulated?
if not, when it stops flowing the next time feel top of tank to see if there is still hot water left top of tank.

sumosi

Thank you very much for your suggestions I will check the areas that you suggested. It does make sense what you said as in the small amount of water remaining say the kitchen tap it blows out then stops and starts which leads me to think there may indeed be a blockage.
Thanks again for your help with this much appreciated.

sumosi

Ok so just ran a bath again (Turned on the immersion heating as its too hot for heating, however its the same effect on the problem )
Starts running hot water for up to less then 1/4 then goes cold for the rest until depletes totally, this all being from the hot tap. The kitchen / bathroom hot taps have no water once the the bath hot tap has ran dry. Cold taps seems to be running normal in all of the house.
Hot Water Tank is insulated in the airing cupboard
House is around 40 years old.
Unfortunately cannot access the attic at the moment where the water tank is as its tricky to get to.
Thanks again

Calahonda52

Thanks for the feedback, very helpful of you.
Now let the post sit till later tonight and see who else has suggestions.

Am a little concerned by the use of the words blow out.
On an open system this may , only may, point to the expansion pipe from the HW cylinder being blocked.

There should be no blow out in a gravity system unless the water is actually boiling in the cylinder or there is some blockage.

No need for unsafe crawling into attic.

As you have less than 50 posts here you can't post fotos or web links.
If you could post some fotos of the pipework in the hot press on some web site and show link as www (dot) website name (dot) com / etc
we can tidy it up

K.Flyer

sumosi wrote: »

Ok so just ran a bath again (Turned on the immersion heating as its too hot for heating, however its the same effect on the problem )
Starts running hot water for up to less then 1/4 then goes cold for the rest until depletes totally, this all being from the hot tap. The kitchen / bathroom hot taps have no water once the the bath hot tap has ran dry. Cold taps seems to be running normal in all of the house.
Hot Water Tank is insulated in the airing cupboard
House is around 40 years old.
Unfortunately cannot access the attic at the moment where the water tank is as its tricky to get to.
Thanks again

There are many possibilities that may be causing or contributing to your problem.
First question is..
Has it always been like this, or is it something that has just started recently?

sumosi

Always been like this since I purchased the property some years back but as have electric shower in the en suite I never addressed this issue until now.
Thanks

sumosi

Calahonda52, Hopefully this will work


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Calahonda52

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Signing off now, will leave it to the experts.

Kimbot

Its very strange that your hot tank is running completely empty, maybe your tank in the attic has a small blockage in it somewhere restricting the flow of water back into your tank.

K.Flyer

sumosi wrote: »

Always been like this since I purchased the property some years back but as have electric shower in the en suite I never addressed this issue until now.
Thanks

You will need to get access to your storage tank in the attic and try to measure the length of the tank, the width, and the height of the water level in the tank in order to determine how much water you actually have in the tank and whether it is sufficient.
Also, if possible, push down on the float in the tank and see if there is a very strong flow of water from the valve.
Also, turn off the cold mains water supply coming into the house. Then check all the cold taps to determine if they are fed from the mains or from the tank.

RJF

From the description it is either an airlock in the pipework, a blockage in the cold feed from the storage tank to the copper cylinder or a very slow filling ballcock. I presume the storage tank is large enough unless someone used a heating header tank - I suppose not impossible- see the WTF thread.
First I would check the ballcock as KFlyer described. Then check that the pipe to the bottom of the cylinder is unrestricted. Lastly check the pipework from the top of the cylinder to the various outlets. I would suggest that all this is a job for a plumber. He should be able to tell in 10 or twenty minutes exactly what the problem is and give you a remedy. A call out charge should probably cover diagnosis and repair unless rerouting or replacing pipework due to airlock.
Calahonda - when you say expansion pipe I presume you mean vent pipe? Definitely a possibility.
You can often get what can be called a blowout when pipework is air locked or even when first filling a system.
Jonnycivic - the cylinder won't run empty unless leaking but flow will stop when header/storage tank is drained/blocked. The cylinder will still be full.
I suspect this is most likely an airlock or slow ballcock.

RJF

Just noticed that gate valve in the photo that says feed to tank. If this goes to the ballcock in the header/storage tank it may be closed or blocked resulting in slow ballcock. Try to turn it clockwise first. If you can't then it's closed or if it turns only a little - nearly closed. Turn it anti clockwise to open it. If it turns or spins freely without coming to a stop then the shaft may be broken and valve in a closed or near closed position - replace. It may be hard to turn if it has not been used in a long time.

sumosi

Thanks RFJ
I just turned the gate valve and it turned fine and then reached its normal alt. Will check all that you mentioned.

RJF

sumosi wrote: »

Thanks RFJ
I just turned the gate valve and it turned fine and then reached its normal alt. Will check all that you mentioned.

Which direction did it turn?
What do you mean by " alt"?
Make sure it is turned fully anticlockwise.

sumosi

Clock wise no problem then reached its stop

RJF

Turning clockwise is closing it. Turn it fully anti clockwise so it is open.

sumosi

ok so it started off closed the only option i have is to turn it clockwise which I done now I have turned it back anti clockwise which it stopped at that stage and remains in that position.

RJF

It must have started off open if you could only turn it clockwise.
If it is now fully anticlockwise that means it is open so leave it there.
I guess this wasn't the problem as it was fully open initially.
Next thing is to check ballcock.
Just noticed you said you have a combi boiler. If so then this must supply hot water to the kitchen tap.
But you said you were getting "blow out" from kitchen tap? Are you sure you have a combi? This doesn't make sense. What is the make and model?

sumosi

Its a GEM Domestic Heating boiler Superior 95 which was in the house when bought, heats the rads and the hot water fueled by oil.

RJF

Ok not a combi.
Gerkos have gone out of business since 08 but the burner is Riello so parts for this as long as the boiler lasts.

sumosi

Thank you, My apologies was sure it was a combi as it provides heating and hot water.Probably will need replacing next year