i have a question

[thompy]

Ok,

lets say the boiler temp is on a high setting, and the water going to HW cylinder is 70 degrees.
If the cylinder thermostat is set at 60 degrees, how does the water cool to 60 degrees?

 

[kevplumb]

it dosen't heat to more than 60 thats what the stat is for

 

[thompy]

hey Kev,

so the stat on the cylinder regulates the temp of the water in the boiler?

 

[Diyisfun]

The water leaving the boiler, needs to be hotter than the water in the cylinder, so heat can be transferred from the boiler to the 'hot water' when the cylinder stat is satisfied the boiler switches off.

Im not a plumber


added
The cylinder stat says I need more heat or I am satisfied.

 

[kevplumb]

no it regulates the temp in the cylinder through a valve
that's probably stuck

have a look here s or y plan

 

[thompy]

i take it that you are referring to the 3 way valve with the small black lever on the side?

if so is there an easy way to test and determine sticking?

 

[kevplumb]

at last some info

most of them you can remove the motor then turn the stat up/down and see if the motor is driving if not put your ear to it and see if you can hear it running
make sure the lever is in the auto position

 

[thompy]

Ah ah,

methinks the penny is finally dropping:
if i had boiler set at highest temp, then the cylinder stat would probably instruct the boiler to switch off quicker (i.e moderate temp = longer burning / heating /// high temp = short burst of heating / burning)

So, if all valves & stats are working, it is irrelevant what the boiler setting is, as the cylinder stat & diverter valve regulate / dictate what the boiler does and the cylinder temp.

What would you suggest to be a normal setting for the boiler ( Ideal Classic - temp goes from 0 -5)

 

[Diyisfun]

The boiler t/stat if set to low, could get to a situation that it can never satisfy the hot water stat & therefor never switch off.
But you are getting there.

 

[thompy]

To summarise then:

if the water in the cylinder is hotter than the cylinder stat, and the immersion is NOT on:

It is likely to be either:

Faulty cylinder stat

or

Faulty diverter valve

 

[kevplumb]

yup

 

[thompy]

nice one boys

I will check the diverter later, i am now a tad suspicious as my wife fills the damn airing cupboard wiv clean washing, maybe that will have summat to do wiv things

 

[Diyisfun]

Now wasnt that a nice post, no off topic, no why dont you search.
Makes life worth living

Mind you still not fixed the problem.

 

[kevplumb]

it stems from here