Hot Water Running Out

[valleycushion]

Is that a secondary return hidden behind the hoover?

Sorry, I'm an idiot, what is a secondary return / let me know what photo I can take to help you see!

 

[valleycushion]

I take it thats a unvented cylinder, if so, post the expansion vessel capacity, once this is known we can calculate the vol of (hot) water that should flow from any HW tap, shut the cold mains to the UVC, then open a hot tap and measure this vol of water, again open the cold mains for a few minutes, then shut it, ensure no one draws off any water, hot or cold, for 30 minutes or so then open a hot tap and measure this volume again, this will give some indication of any leaks etc.

Thank you, I've no idea what any of this means to be honest, but the expansion vessel capacity is attached.

FWIW when the heating / hot water is running that cupboard is nicely toasty, but it then gets cold during the day when it's not running. I could well be misremembering this, but I always remember that cupboard being warm throughout the day even when on the schedule we're currently running.

 

[valleycushion]

So all your consumption is hot water heating only?

Main consumption in these months is hot water from a tap, we've only just started blasting the heating for a short amount of time in the morning and evening

 

[valleycushion]

What exactly does this mean?
When the cold tap is turned on, cold water should come out immediately. If it's a mixer tap that's just been used for hot water, then perhaps a second or two to clear any hot water left in the tap body.
Anything longer that that and something is fundamentally wrong.

It might be nothing, but when a cold tap is turned on after running hot water, I normally have to run it for a longer amount of time than I remember doing, to get it to be cold. A few seconds maybe.

 

[valleycushion]

Your gas usage for Sept 2024 looks extremely low. I live in a similar size house to you and my gas usage is around 500kWh in September. How are you measuring gas usage and how are you dividing the usage between heating and hot water?

Perhaps this helps? We have only really in the last few days started running the heating for a few hours in the morning and evening, for all of September we had no heating and everything was just hot water.

 

[Murdochcat]

Weekly consumption doesn’t really help. Could you show daily usage?

 

[valleycushion]

Weekly consumption doesn’t really help. Could you show daily usage?

Here are some examples for you which I hope help

 

[Johntheo5]

Sorry, I'm an idiot, what is a secondary return / let me know what photo I can take to help you see!

A secondary return is used with a bronze circulating pump which comes on normally on a timer and circulates the cylinder water around the house to ensure you have hot water almost immediately on opening any tap, it will absolutely flatten the cylinder hot water if not timed properly so look for a pipe about half way up the cylinder take a few photos.

 

[Daveydub]

On those Center ones (I hate spelling it that way) the secondary return tees into the cold feed. There is a horizontal pipe behind the cylinder and the hoover hides where it goes to. Does it tee into the cold supply pipe?

 

[Johntheo5]

Here are some examples for you which I hope help

Allowing for boiler efficiency and cylinder losses you seem to be using ~ "10kWh" of HW/day, this equals to 187LPD, heating the water from 14C to 60C or a consumption of ~ 307LPD assuming HW used at 42C. If 4 people, = 77LPD/person of HW at 42C.

 

[valleycushion]

Allowing for boiler efficiency and cylinder losses you seem to be using ~ "10kWh" of HW/day, this equals to 187LPD, heating the water from 14C to 60C or a consumption of ~ 307LPD assuming HW used at 42C. If 4 people, = 77LPD/person of HW at 42C.

Thank you. In laymans terms, what does this mean? We have two kids and two adults. The kids shower every other day (short showers) on an evening, the adults shower in the morning, again pretty short.

 

[valleycushion]

A secondary return is used with a bronze circulating pump which comes on normally on a timer and circulates the cylinder water around the house to ensure you have hot water almost immediately on opening any tap, it will absolutely flatten the cylinder hot water if not timed properly so look for a pipe about half way up the cylinder take a few photos.

These are all the pipes going in and out of the water cylinder. I have some pipes going off into the cupboard which have metal boxes around part of them - could it be that? I've never had to set a timer up other than on the tado - so I might be missing something?

 

[valleycushion]

On those Center ones (I hate spelling it that way) the secondary return tees into the cold feed. There is a horizontal pipe behind the cylinder and the hoover hides where it goes to. Does it tee into the cold supply pipe?

Good morning- It goes down the side of the cylinder then into the floor. (also we found where all our pegs went!)

 

[dilalio]

Check for a passing mixer valve.
Thermostatic shower or bath filler.

 

[valleycushion]

Check for a passing mixer valve.
Thermostatic shower or bath filler.

Sorry, I'm very much an amateur here, I'll try get my plumber around next week to do this but can you put this in idiot terms for me and tell me what that is and how to check it?!