Unvented Cylinder set up via gas system boiler and time clock

[Space_Goat]

Hi

I wanted some steer from he forum for my set up.

2 storey house now extended on ground and a loft conversion.

New plumbing install as of 18months. Worcester bosch 8000 life sysem boiler via natural gas. Time clock with HW / CH split, 7 day digital. 250litre Gledhill Select Indirect. Immersion with on off (really need to change this to a timed boost type plate).

Ground floor is all UFH. Utility , GF WC and kitchen. Boiler and tank are on ground.
1st floor has main bathroom with bath and thermostaic shower over.
2nd floor has ensuite with shower.
1st and 2nd.
Baths are rarely a thing, showers x 4 per day and kitchen use main draw on water.

Thermo on tank is clicking at approx 42degrees, i have it set to 55.
I have set HW to come on at 6am for an hour. Noon for an hour and 5pm for an hour.

Questions:
1 do i need to increase amount of hours?
2. Is supplying at 42 deg unsafe?
3.Heating is off as house is warm enough, when heating resumes shold i match the heating on times with the HW on tines, would this be more efficient?
4. Would you see any benefit occasionally hitting the immersion?

This is all against an efficiency back dropwith rising energy prices, i want to get the setup right, safe and cost effective!

Thanks!

 

[ShaunCorbs]

You need to heat the tank to 60 to kill off any legionella as it likes 30-40 dc temp

Ideally if the hot water is on by it’s own should easily reheat within the hour providing the boiler is 20kw

 

[Space_Goat]

You need to heat the tank to 60 to kill off any legionella as it likes 30-40 dc temp

Ideally if the hot water is on by it’s own should easily reheat within the hour providing the boiler is 20kw

Thanks Shaun

Its a 30KW system boiler supplying into the 250litre Gledhill.

I checked this morning and it was 43 deg on the Gledhill insulated tank.

What temp of water do you think i should set my system boiler to produce at as obviously thats a factor (its getting cooled by the existing water it mixes with)

Thanks

 

[ShaunCorbs]

65 and cylinder set to 60

You could leave the hw on all day so after each shower your heating up what you’ve used instead of heating up from cold after let’s say 2-3 showers ?

 

[Space_Goat]

Thanks again Shaun

That sounds dear (boiler on more?) , but maybe is a mindset thing.

Is that the way you would typically recommend setting HW cylinders?

I also wonder if in a traditional gravity system with a copper cylinder, more often than not id say the water in it would be lower than 50deg, would you agree?

If that is the case, why wouldn't there be more bacteria problems?

Thanks again, really trying to balance cost and safety here and looking at all angles to get best sensible setting to lock in!

 

[ShaunCorbs]

You may think but your heating up less water so overall on less or about the same depending on cylinder

Is a copper cylinder used to have a higher boiler temp eg 70 dc going to it and was set for 60 dc (well should be )

 

[exedon2]

Have a look as E S I digital cylinder thermostats they do a model that heats cylinder over 60c for 1hr a week.
So can be left set at a lower temperature.
As you might expect bit of re wiring as requires permanent live.

 

[Space_Goat]

Have a look as E S I digital cylinder thermostats they do a model that heats cylinder over 60c for 1hr a week.
So can be left set at a lower temperature.
As you might expect bit of re wiring as requires permanent live.

Thanks for that, will have a look.


I was contemplating programming timer for it to run all day for only one day ( say every SUNDAY) with Thermo set at 60.

Then i could drop back to current use knowing at least one day per week 60degrees was reached

 

[Space_Goat]

Thanks for that, will have a look.


I was contemplating programming timer for it to run all day for only one day ( say every SUNDAY) with Thermo set at 60.

Then i could drop back to current use knowing at least one day per week 60degrees was reached

This is the as existing thermostat: caleffi-dual-thermostat-dhs803

Its wired into a Danfoss Wiring Centre WB12

Could the ESI go into the Danfoss Wiring Centre in a 'like for like' arrangement do you think?

 

[exedon2]

Straight forward replacement
You will need to use a 4 core flex to connect.
In junction box grey connections off motorised valves should be permanent live check first!