Stat Temp / Hot Water help

GregStarz

Good afternoon guys,


I changed my cylinder thermostat yesterday as it was broken, it's working fine but after doing internet research apparently it should be set at 60-65? Yesterday evening I put the hot water on for an hour and ran a bath, had nice hot water but literally not enough to fill the bath full, is this normal or should I increase the temperature?


I'm trying to figure out what temp my cylinder/boiler thermostats should be set at and also how long I should have the water on in the morning/evening, in the past 30 mins was enough to cover us but more recently it doesn't seem enough hot water now :shocked:


(ps - my boiler thermostat was set at 78 but I was told this was too high so reduced it)

Ruski

It's more to do with the size of your cylinder - is it capable of supplying a whole bath full of hot water (c. 180l)
60/65 is normal.

Russ

Heedtheadvice

...and it depends on the boiler temperature, time heating, controls working ok etc. What type of boiler? What temperature is it set to? Is it heating anything else at the same time? i.e rule out other issues too!

It would also seem that you will have a lower 'quantity' of hot water available (to mix in with cold in the bath) to get a comfortable bathing temperature if you have reduced the stat to the correct setting.

GregStarz

I've adjusted the temperature on my boiler and the thermostat as I did some research and apparently my temps were too high. My cylinder thermostat was originally at around 80 (I think, but the twisty dial had snapped so I honestly don't know, it could have been less) so when I fitted new cylinder thermostat I set it at 65 which seemed the norm.


After doing this research I noticed that my boiler temp was also too high (80) so I've adjusted that down to 70.


This morning I had the water on for one hour, there was enough hot water for my other half and just enough hot water for me to have my shower 1hr later (it just started to get cold)


So, is this right or should I crank everything up? is it normal for water to be on for 1hr every morning? I used to only have it on for 30 mins each morning.


I will test a bath tonight but I imagine with cylinder set at 65 and boiler at 70 I may struggle to complete a full bath (never had this issue before)

getmore4less

The hot water rises to the top of the tank.

the top bit will get hot quite quickly but the rest of the tank will be cold(er).

What you can do to get a rough idea is after the morning heating cycle(+ say 10 mins) before drawing any water play with the tank stat and you will hear it click* which will give an idea of how hot the bottom of the tank got.

The hotter the boiler temp the quicker the tank heats up.

The other thing that hinders the water heating cycle is if the heating is on at the same time as they share the water.

the idea of a tanks stat is to turn of the heating when the bottom of the tank hits temp so just leave it on for longer, have it go off around the time you draw the morning water, if you don't want a fresh tank till the evening.

I have a system that can control the temp and time so have it hotter for bath(50c) and colder for shower(40c)/other.... the top of the tank gets hotter than this we find it is enough for our needs and if we run out/guests we boost it up to 55c.
I set the time I want the water hot, the system guesses how long it will take to heat up based on previous cycles.

edit: * if you don't hear it click turn it down then turn the water back on(boost) and slowly turn the stat till the heating kicks in.

GregStarz

Oh I've just noticed something, the rads are getting hot when only the water is on so I wonder if this isn't helping the situation?

getmore4less

if you have a mid position valve check the actuator has not failed and/or the valve is sticking.

Head_The_Ball

GregStarz wrote: »

Oh I've just noticed something, the rads are getting hot when only the water is on so I wonder if this isn't helping the situation?

That could mean that the diverter valve has failed and is not shutting off the water to the radiators when you want hot water only.

Do you know how to find and check that?

The diverter valve allows hot water from the boiler to go to 1) The hot water cylinder 2) the radiators or 3) both, depending on what the various thermostats demand.

Some systems prioritise hot water over heating so only 1 or 2 apply.