Worcester Bosch Greenstar 8000 SYSTEM boiler settings etc

[RogW]

Hi

A few questions . . . !

Recently moved in to a house that has a recently installed W/B Greenstar 8000 Style 35kw SYSTEM boiler. It is run from an old (non smart) Honeywell timer. A very large Ariston tank is fitted.

What is the optimum temp setting to have on the boiler? (can find lots about Combi boilers - but not system).

Only the heating light goes on on the boiler (not the hot water - there is a dial control at the base of the h/w tank to control the temp on that) - is that a normal setup?

There are 20 rads in the house, each has a Tado on and I have set each to specifics for each room (Tado brought with me from previous house) Its a big, cold old house, solid walls etc so its as thermally efficient as an old garden shed!

What smart control would be wise to fit so I have more control? - I gather that Tado all not work with the boiler. So Nest / Hive / Bosch own system ?

Any thoughts / help welcome!

Thanks!


Roger

 

[muggles]

That's rather a large boiler for a 20 radiator system! The Bosch Sense 2 would definitely improve things from an efficiency point of view although it won't give you app control.

 

[RogW]

Yes - a biggish boiler - but also big rooms with very high ceilings (and 3 x bathrooms . . .) Out of the 20 rads - 18 are double rads 1.4m+

Not my choice of boiler - its what was fitted just prior to our purchase recently.

 

[JonathanM]

What is the optimum temp setting to have on the boiler? (can find lots about Combi boilers - but not system).

For efficiency, and perhaps comfort, you want a low flow temperature. Maybe 50C, or even lower. The problem with doing this with a system boiler, is that the hot water cylinder may be too cool, both for washing effectively, and also because there is a risk of contamination by legionella bacteria. The cylinder can only be as hot as the water flowing out of the boiler. But there are ways around it, either by installing extra kit, or using an immersion to sterilise the cylinder once a week. (Although my immersion has only ever seemed to heat the top 40% or so of the cylinder, but this seems to be something unusual about mine.)

Only the heating light goes on on the boiler (not the hot water - there is a dial control at the base of the h/w tank to control the temp on that) - is that a normal setup?

This sort of leads on from above. I think there are two ways of setting up this boiler. In a basic configuration, I think it only produces water at one temperature. So the same temperature water flows to both the radiators and the cylinder. That sounds like your situation. But by installing extra kit and controls you can have two different water temperatures, one for when water is flowing around the radiators, and another for when the cylinder is being heated. So you can have the efficiency of a low temperature for the radiators and still have the hot water cylinder at a safe temperature.

EDIT: hopefully somebody will confirm if this second bit is correct!