Does water heating up quicker with heating turned off?

[Mimi12]

We have a Baxi condensing boiler. The heating is on most of the time in this cold weather and we turn the heating on for half an hour on a daily basis. I have a theory that the water heats up quicker if we turn the heating off ... my partner disagrees. Can someone please help us solve the argument!

Many thanks.

 

[MickyP10]

Hot water takes longer to get to desired temp if heating is on too. Well, does here.

Radiators take longer to warm up the more you have turned on. Same principle...

 

[Dan Robinson]

It will depend more on he heat load of the property, output of the boiler and the absorption capacity of the cylinder coil.

Not to mention the control regime.

 

[dcawkwell]

From stone cold it will take longer with the heating on as the boiler is also busy heating the volume of water in the radiators.

If you are heating a tank as the heating is already hot then it depends
on the heat loss of the radiators. If the boiler is supplying say 12kw of heat to the radiators and then needs to find 20kW of heat to start heating the tank
chances are your boiler isn't that big so it will also take longer.

Even if the boiler exceeded the 32kW you then have to consider circulation and how well balance the tank and central heating are to supply the correct flow.

In my house I set the hot water to come on 15 minutes before the central heating so the tank will be virtually hot before the central heating kicks in.

 

[Agile]

I always advise setting HW to start heating 30 min before the Ch is timed to start.

Of course for DIA that means the HW can still heat when the CH is on but will probably already be hot or only need a small amount of power.

It will usually mean that at the CH start up the entire boiler output can be dedicated to heating up the rads faster.

 

[OwainDIYer]

Mostly depends on the control system: some will divide the boiler output between the radiators and the hot water; others will switch the output to one or the other, in which case the hot water usually gets priority.

 

[Mutley56]

Does this advice about setting the hot water to heat up before central heating apply to system boilers too or only combi boilers?

Thanks.

Mutley56

 

[Mikefromlondon]

We have a Baxi condensing boiler. The heating is on most of the time in this cold weather and we turn the heating on for half an hour on a daily basis. I have a theory that the water heats up quicker if we turn the heating off ... my partner disagrees. Can someone please help us solve the argument!

Many thanks.

As your question was slightly misleading, i.e. you omitted the word " water heating" see below I have pasted your question with the missing word in bold, so my original answer was incorrect, now the correct answer to your question is below your edited question below.

We have a Baxi condensing boiler. The heating is on most of the time in this cold weather and we turn the water heating on for half an hour on a daily basis. I have a theory that the water heats up quicker if we turn the heating off ... my partner disagrees. Can someone please help us solve the argument!

Many thanks.

Yes during cold weather, when you have your main heating on, then the hot water tank will take longer to heat up, because the boiler's primary flow is split between the two a) the radiators, b) the hot water storage tank, so each one gets approx half the boiler's flow, so the hot water will take longer to heat, as well as the radiators will take longer to heat up if both were switched on at the same time from cold.

 

[SimonH2]

Does this advice about setting the hot water to heat up before central heating apply to system boilers too or only combi boilers?

It doesn't apply at all to combi boilers as they heat the water on demand - ie there isn't a storage tank to heat up.

 

[Mutley56]

Tnx SimonH2,

I realise now that I misread the original post as Combination boiler as opposed to Condensing boiler that was actually written. Hence, in hindsight, my daft question.

Tnx again.

Mutley56