Condensing Boilers - Best Heating & Water temperatures

[Manny Haines]

Does anyone know what the optimum temperatures for a condensing Bosch boiler should be set at?

The internet has various people saying 80 for Heating and 65 for water down to 65 for heating and 50 for water.
People stating the lower settings use less gas and actually make the condensing boiler more efficient as that is they way the have been designed?

But there doesn’t seem to be one standard train of thought, with some people saying the lower the setting then that makes the boiler less efficient, so there is some confusion about the matter.

With regards to the hot water setting, the thinking is, why have water being heated up so high that you then have to cool down with cold water, makes sense to me.

I’m currently on 70 heating and 55 water.
Could I be needlessly be burning fuel and drop these to 65H & 50W?

[Gelatoni]

Originally Posted by Manny Haines

Does anyone know what the optimum temperatures for a condensing Bosch boiler should be set at?

The internet has various people saying 80 for Heating and 65 for water down to 65 for heating and 50 for water.
People stating the lower settings use less gas and actually make the condensing boiler more efficient as that is they way the have been designed?

But there doesn’t seem to be one standard train of thought, with some people saying the lower the setting then that makes the boiler less efficient, so there is some confusion about the matter.

With regards to the hot water setting, the thinking is, why have water being heated up so high that you then have to cool down with cold water, makes sense to me.

I’m currently on 70 heating and 55 water.
Could I be needlessly be burning fuel and drop these to 65H & 50W?

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We are currently 70H, 60W. The heating had an eco symbol by that mark, so we've kept it at that to save costs.

Water we can probably bring down even further, but haven't experimented yet. Certainly don't need it scalding.

We are currently using approx 600kWh gas per month, but obv everyone is different.

[Stitch & Smudge]

We’re sitting at 70 and 50. Water plenty hot enough. WB Greenstar 30i.

[Chunky81]

I have a system boiler so temp set covers both @ 69. Installer said this was optimal temp. Think he said it needs to be above 65 for the condenser side to work properly.

[Manny Haines]

Originally Posted by Gelatoni

We are currently 70H, 60W. The heating had an eco symbol by that mark, so we've kept it at that to save costs.

Water we can probably bring down even further, but haven't experimented yet. Certainly don't need it scalding.

We are currently using approx 600kWh gas per month, but obv everyone is different.

See more...

Thats my machine the
WB Greenstar 30i.

I’ve just noticed its got an Eco button so I’ve pressed that, no idea what it does, but here goes.

So, Waters 50 and Heating 70.

[wobblywibbly]

I have seen a lot of people on various threads with low water temperatures I believe it should be above 60 or you run the risk of legionares disease being present

[Manny Haines]

Oh, I missed that.
Hells bells, more confusing. lol.

[huntmj]

Originally Posted by wobblywibbly

I have seen a lot of people on various threads with low water temperatures I believe it should be above 60 or you run the risk of legionares disease being present

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My understanding also is that water needs to at 60 minimum to avoid legionaires disease which many will remember caused a problem some years ago.

[Manny Haines]

See what I mean, its all very confusing.
I read one thing and I thought the >60 was for the heating, not the water?

[Floridadot]

A couple of years ago my regular plumber came to service the condenser boiler at a house we’d moved into. He said not to have the radiator heating set at the ‘e’ setting, he put it at about 83 degrees and said that the lower the temperature that’s set at the longer it will take the house to get to temperature so the boiler would actually be on for longer. Makes sense I suppose the water he put at about 72.

I’ve just left it as it is since then but the house does heat up quicker than it did when set on ‘e’.