DHW what is the right temp?

[Steelmasons]

to check the flow rate of the boiler, turn the hit tap on fully, and either see how many seconds to fill a litre jug, of fill a bucket for a minute, and see how many litres are in it. If it's higher than 12 litres per minute, then you need to adjust the 2nd pipe from the right on the boiler (or the one that gets hot when the taps turned on).

Pressure/flow rate will change throughout the day due to peak demand..

The thermostat only controls the times that the heating comes on

If it were a programmable stat then yes.

I'm not sure about the boiler, but it will have time periods on, and very likely what are called set back periods for when the heating would normally be off. You'd set the thermostat so that you want say 21C at 7:30 in the morning, and then you have it go off at maybe 9am when you go to work, but if it's a set back system, then you'd change it to go to 5C at 9am, and then set it to be 21C at 4:30pm, and then back to 5C at 10pm when you want the heating to go off at night Let me know the model no.

Make your mind up...would it be the room stat or the boiler that controls the time periods??
If I were you I'd keep quiet..

 

[Doggit]

You obviously know fook all about boilers

Well I can't know fook all if I know about the adjustment valve can I, bit of a contradiction there, just got the wrong pipe. As the the legionnaires, Agile brought that up earlier.

Sorry Steel, tiredness. Wireless stat of course, which will invariably be programmable.

 

[Steelmasons]

Well I can't know fook all if I know about the adjustment valve can I, bit of a contradiction there, just got the wrong pipe. As the the legionnaires, Agile brought that up earlier.

With all due respect Doggit and I hope you don't take this the wrong way but you know fook all TBH..
Sorry...

 

[JOB6]

Thanks again and later on I will see how long it takes to fill a bucket of hot water. The model of the boiler from what I can see is:
Vokera compact 29a combi boiler

 

[Doggit]

Now why should I take it the wrong way. I know what I know, and I get by quite happily and help out where I can, unfortunately, sometimes I just put it down the wrong way - asperers, autistic, and dyslexic all at the same time, not easy being me believe me. I have no problem with someone correcting me, and will happily apologise for having made a mistake, just don't see why I should be abused for it though, a straightforward correction is all that's necessary.

 

[Madrab]

Job, you have vokera's programmable room stat. comprehensive instructions here -

 

[picasso]

Ok doggit a straight forward correction , wireless stats aren't invariably programmable

 

[JOB6]

I ran the hot water tap in the bath and it filled an 11 litre bucket in 50 seconds is that okay? The only thing which turns on the boiler pipes is the cold water inlet stopcock nothing else that I can see. The cold water inlet stopcock (picture attached) seems to control the hot water pressure throughout the flat, when I turn it all the way clockwise it turns the hot water off, should I just turn it all the way anti-clockwise?

 

[Madrab]

Job, avoid playing with the valves under the boiler. Turn the dial up to 10, if the hot water still isn't hot enough turn the hot tap down a little, it will get hotter

Just leave the cold inlet open Job. Your L/Min is fine too

 

[Doggit]

And there's the problem, you've got a flow rate of 13.2 litres per minute for a boiler that's designed to run at 11.9lpm. The valve doesn't control the water pressure, but actually the water flow, so open it fully, and then turn back fractionally, but then as I don't seem to know what I'm doing, I'm sure someone will tell you a better way of doing it.

 

[Jay32Heating]

Most combi boilers at max will give you between a 30-40 degrees rise from the cold water incoming main temperature at the specified flow rate by the manufacturer which at a guess your boiler will chuck out around 12 litres a min max. so slowing down the flow rate at the tap will slow down the flow rate the cold main goes through the boiler giving it more time to heat up so it will be slower out the hot tap but at a higher temperature. so in a nutshell if the cold water temperature is 10 degrees then at max flow rate the boiler will provide 40-50 degrees out the hot tap. if the plate heat exchanger is a bit blocked up too it will affect the heat transfer. hope this helps

 

[Madrab]

Can't fault your math Doggit but that boiler has a flow restrictor on the inlet that ensures it is sits at the delivery rate that the plate can deliver @ a 35 deg rise. It's so the delivery aligns with the specc'd rated HW output. Chances are the flow measurement was out a little. It also removes the need for flow adjustment at the boiler.

 

[Steelmasons]

just don't see why I should be abused for it though.

Abused??? What was said that you felt was abusive??
Abusive is when the foreman throws the 48" stilsons when you fook up.....let me tell you it fookin hurts and you soon learn.......
Some on here don't know the true meaning of abuse FFS..
As my Mum used to say "sticks and stones may break my bones but names will never hurt"....

 

[JOB6]

So should I then adjust it by turning the black square 'water flow, so open it fully, and then turn back fractionally'. After 5 turns the stopcock is fully open (anti-clockwise) how many turns should I turn it clockwise from the fully open position?
Specs of the boiler are:
Heat input Kw:29.50
Maximum inlet pressure: 6 bar
Minimum inlet pressure: 0.15
Minimum flow rate: 21/min
Flow rate at 35c: 12.1 in one minute
Power consumption watts: 140

Also Madrab thanks for the video link of the thermostat that is exactly what I needed as it makes more sense than the booklet I have, all of the info is much appreciated and wishing you all a great weekend for helping a silly sod like me.

 

[Jay32Heating]

So should I then adjust it by turning the black square 'water flow, so open it fully, and then turn back fractionally'. After 5 turns the stopcock is fully open (anti-clockwise) how many turns should I turn it clockwise from the fully open position? Also Madrab thanks for the link of the thermostat that is exactly what I needed as it makes more sense than the booklet I have, all of the info is much appreciated and wishing you all a great weekend for helping a silly sod like me.

Keep your stop taps and valves fully open... just crank back you hot taps slightly to reduce the flow rate slightly and that will increase your hot water temperature