Heating HW and rads simultaneously - more efficient?

blindsider

I was advised recently that I should heat Hot Water at the same time as my central heating is switched on (radiators).

We have natural gas, a Vokera Mynute Condensing boiler (2009) and a very well insulated 300l water tank.

Normally, I would heat hot water for 1hr per day - early morning. I make sure that the water is above 60 degrees a few times a week to avoid anything nasty like Legionella.

Should I now change to heating Hot Water in the evening when the central heating is on - maybe 3hrs? Is this more efficient?

Any other tips?

Thanks!

Mumser

I’m bumping this query as I’m interested in any thoughts on it too.
Thanks

Wearb

There's going to be very little in it either way, but to be pedantic, it will be a bit more economical to do both at the same time.

This depends on when you want the hot water and how well the cylinder is insulated. eg Not much point in heating the water 8 hours before you need it, only to have it cool down by the time you need it.

KungPao

You sure the Volkera is condensing? I have a Mynute, thought it was the older more inefficient type. Mine’s scheduled for replacement soon either way.

The way I see it, if one or two people are having showers or a bath in the evening from this heated water, just leave it heat both. If the hot water is only for general use ie taps, probably best to heat separately for shorter times if the system allows.

I just heat both at same time and use hot water for shower. The electric shower won’t be used so much now until April or so - more just for quick use in the mornings.

Keep doing what your doing, running both at the same time often leaves a heating system under performing as your sending heat to the Cylinder.

blindsider

KungPao wrote: »

You sure the Volkera is condensing? I have a Mynute, thought it was the older more inefficient type. Mine’s scheduled for replacement soon either way.

The way I see it, if one or two people are having showers or a bath in the evening from this heated water, just leave it heat both. If the hot water is only for general use ie taps, probably best to heat separately for shorter times if the system allows.

I just heat both at same time and use hot water for shower. The electric shower won’t be used so much now until April or so - more just for quick use in the mornings.

Good question! I always assumed it was and this seems to agree:

https://www.homeheatingguide.co.uk/efficiency-tables?model=015075#:~:text=Vokera%20Mynute%2025%20HE%20Boiler%20Efficiency%20Rating&text=The%20Vokera%20Mynute%2025%20HE,Gas%20as%20its%20fuel%20source.

The Vokera Manual also mentions a 'Condensing Drain'

KungPao

blindsider wrote: »

Good question! I always assumed it was and this seems to agree:

https://www.homeheatingguide.co.uk/efficiency-tables?model=015075#:~:text=Vokera%20Mynute%2025%20HE%20Boiler%20Efficiency%20Rating&text=The%20Vokera%20Mynute%2025%20HE,Gas%20as%20its%20fuel%20source.

The Vokera Manual also mentions a 'Condensing Drain'

Ah yeah, looks like yours is alright - my one is an earlier model.

corkgsxr

Imo the condensing boiler should be under pressure idea is wrong.

It's fails to take into account boiler will modulate.

Run it how you were.

bobbyy gee

only heat water when you need it it only takes 10 minutes