Should I switch off the boiler in the summer?

[Mr Punter]

I have a new four storey townhouse with a system boiler in the roof and a cylinder on the first floor.  Bathrooms on first and second floor, kitchen on the third.

 

The boiler seems to fire up a fair bit for the hot water and I wondered if it would make sense just to use the immersion in the warmer months?

[Nickfromwales]

1 hour ago, Mr Punter said:

I have a new four storey townhouse with a system boiler in the roof and a cylinder on the first floor.  Bathrooms on first and second floor, kitchen on the third.

 

The boiler seems to fire up a fair bit for the hot water and I wondered if it would make sense just to use the immersion in the warmer months?

If you put the immersion on a timer then it would reduce fatigue on the boiler, but tbh, thats what the boiler manufacturers made it for so its not like it needs any babysitting  What type of cylinder do you have? If it routinely runs cold then electricity will work out more costly, but if its a reasonably efficient UVC then it may be worth considering.  

[Temp]

Perhaps consider..

a)Adding more insulation to the cylinder?

b)Setting the time clock so the hot water is only on first and last thing in the day?

[Mr Punter]

9 hours ago, Temp said:

Perhaps consider..

a)Adding more insulation to the cylinder?

b)Setting the time clock so the hot water is only on first and last thing in the day?

 

I don't have much prospect of the extra insulation as the cupboard is very tight.  I have got in mind to insulate all the pipework in the cupboard though.

 

Time clock is definitely going to happen although it is v. tricky to programme.

[Mr Punter]

On 30/07/2018 at 20:22, Nickfromwales said:

What type of cylinder do you have? 

 

I just had a look and it is a slimline Joule Cyclone Indirect.  Only C rated, but it needed to be shoehorned into a small cupboard.

[Carrerahill]

On 30/07/2018 at 18:21, Mr Punter said:

I have a new four storey townhouse with a system boiler in the roof and a cylinder on the first floor.  Bathrooms on first and second floor, kitchen on the third.

 

The boiler seems to fire up a fair bit for the hot water and I wondered if it would make sense just to use the immersion in the warmer months?

 

This will take some meter readings to get your real life costs and work out which is cheaper.

 

Gas (assume gas boiler?) is far more efficient for heating than electric.

 

Let's say the boiler is using a unit of gas per heating cycle at 3-4p and the immersion heater takes maybe an hour at 3kW at 12p an hour then you need to work out how often does the immersion come on i.e. would 1 hour at 3kW (36p lets say) heat you enough water for the average day? Or would it be better to blast the boiler a couple of times a day but it only costs a combined 24p?

 

So how do you do this real life check.

 

I would take both meter readings at say midnight tonight and again at midnight tomorrow using the gas boiler, then kill the boiler and switch to immersion and do a 24hr period meter read again - I would try and do it on a standard weekday and try and keep costs similar - so for example cooking a full roast with the oven on for 4 hours on one of the nights is going to give you a false reading.

 

I don't know what your household is like and how many of you there are but another option is to wait until you can more or less control all the variables and try and replicate similar loads on the electric in particular each night. As for gas it's easy, you could probably do a day with only hot water and don't use gas for anything else so you know your gas consumption is only hot water. Another option is to take both readings today with gas boiler, and then take the readings again same time in 1 week and then switch to electric and then do another weeks readings - a weeks view would probably be more accurate and would account for variations in cooking habits etc.

 

Another thing to bear in mind is that boilers like to be used, leaving a boiler off all summer can also lead to issues. I cycled my boiler last week for 10 mins just to get a flow through the system and actuate all the valves etc. We have a combi-boiler so the boiler is on demand and is in use everyday anyway but the CH circuits are not. I don't actually understand why anyone would install anything but a combi setup. The idea of stored hot water in this day and age seems madness.

 

 

 

 

 

 

Edited August 7, 2018 by Carrerahill

[Mr Punter]

2 minutes ago, Carrerahill said:

The idea of stored hot water in this day and age seems madness.

 

 

The boiler is on level 4 in a roofspace plant room, with kitchen on level 3, bathrooms on levels 1 and 2.  The hot water tank is on level 1.  The only other option for the boiler was level 0 and I did not want to wait an age for hot water.

[Carrerahill]

13 minutes ago, Mr Punter said:

 

The boiler is on level 4 in a roofspace plant room, with kitchen on level 3, bathrooms on levels 1 and 2.  The hot water tank is on level 1.  The only other option for the boiler was level 0 and I did not want to wait an age for hot water.

I love that your reply is only in response to the throwaway comment about stored hot water! Not the oodles of advice and answers to your question...

 

 

[Mr Punter]

50 minutes ago, Carrerahill said:

I love that your reply is only in response to the throwaway comment about stored hot water! Not the oodles of advice and answers to your question...

  

 

 

 

I am also a fan of combis and was explaining why I did not fit one. Your advice was much appreciated. There is currently no timer on the immersion so the proposed test would be tricky. Cooking is electric oven and gas hob. There are 4 in the household.

 

From what you say about the downside of leaving the boiler switched off, I will try the twice daily blast on the boiler if I can get the timer to do what I want it to.

[Nickfromwales]

6 hours ago, Carrerahill said:

I love that your reply is only in response to the throwaway comment about stored hot water! Not the oodles of advice and answers to your question...

 

 

A little abrasive, perhaps? 

 

7 hours ago, Carrerahill said:

I don't actually understand why anyone would install anything but a combi setup. The idea of stored hot water in this day and age seems madness.

Maybe because a hot water system in particular should be specified to meet the needs and requirements of the both the size of dwelling and number of occupants / DHW consumption patterns. 

Much as I like a good combi, they're less than brilliant at producing hot water. Plus, in a 4-storey house, if the DHW consumption is high then the space heating would not get serviced sufficiently ( as your probably aware, a combi cannot produce heating and DHW simultaneously, so whilst a hot tap is running there is no output to the heating ) so they're not really suitable for anytging bigger than a 2-3 bed  ( 2-3 occupant ) dwelling. After you need more than one shower the combi falls flat on its arse. 

Stored hot water ( cylinder / Sunamp ) is also a means to absorbing excess PV production, whereas a combi just sits there with a daft look on its face as it burns gas not electricity, so again, not suitable in that situation, ( if you like 'free' hot water for eg ). 

 

To say that everyone should suffer a combis poor DHW output is where any madness lays IMO. . 

[Carrerahill]

12 hours ago, Nickfromwales said:

A little abrasive, perhaps? 

 

Maybe because a hot water system in particular should be specified to meet the needs and requirements of the both the size of dwelling and number of occupants / DHW consumption patterns. 

Much as I like a good combi, they're less than brilliant at producing hot water. Plus, in a 4-storey house, if the DHW consumption is high then the space heating would not get serviced sufficiently ( as your probably aware, a combi cannot produce heating and DHW simultaneously, so whilst a hot tap is running there is no output to the heating ) so they're not really suitable for anytging bigger than a 2-3 bed  ( 2-3 occupant ) dwelling. After you need more than one shower the combi falls flat on its arse. 

Stored hot water ( cylinder / Sunamp ) is also a means to absorbing excess PV production, whereas a combi just sits there with a daft look on its face as it burns gas not electricity, so again, not suitable in that situation, ( if you like 'free' hot water for eg ). 

 

To say that everyone should suffer a combis poor DHW output is where any madness lays IMO. . 

 

OK, tarring everyone with the one brush situation here. Fair enough if you are generating hot water or electricity and need storage, or if you are building a larger house, but as a general argument, i.e. across the general house building industry of the UK, for a typical house with a couple of bathrooms then I can't understand why they bang in tanks (well I can - because [ certain large scale developers ] can get away with those little junky GlowWorm boilers that cost £450 and a £180 tank). I'd say generally self-builder houses do require storage because by nature of what we are doing we are going to put in solar and we are building bigger houses etc. but we are the minority and we do things quite differently but not all of self builders are building big houses, yet these calorifers appear as commonly as a roof on a house!

 

We have the W/B Highflow boiler on the first floor to reduce runs and the kitchen is directly below it, the bathrooms are arranged so that services are back to back etc. and to minimise pipe runs, hot water can be delivered comfortably to 2 showers simultaneously at good pressure and heat. 

Edited August 8, 2018 by Nickfromwales
Please do not specify or name a company negatively if only offering opinion

[Carrerahill]

17 hours ago, Mr Punter said:

 

 

I am also a fan of combis and was explaining why I did not fit one. Your advice was much appreciated. There is currently no timer on the immersion so the proposed test would be tricky. Cooking is electric oven and gas hob. There are 4 in the household.

 

From what you say about the downside of leaving the boiler switched off, I will try the twice daily blast on the boiler if I can get the timer to do what I want it to.

Mr Punter, it was said with a comedy satirical tone when I said "I love that your reply is only in response to the throwaway comment about stored hot water! Not the oodles of advice and answers to your question..." if we had been face to face it would have been of a friendly nature. Nickfromwales pointed out it sounded abrasive and I didn't mean it like this.

[Nickfromwales]

1 hour ago, Carrerahill said:

We have the W/B Highflow boiler on the first floor to reduce runs and the kitchen is directly below it, the bathrooms are arranged so that services are back to back etc. and to minimise pipe runs, hot water can be delivered comfortably to 2 showers simultaneously at good pressure and heat. 

Agree, but quite a lump she is ( floorstanding iirc ? )

I go for the Vaillant 938 ( wall-hung ) heat-store combi which does two adequate showers, IF the cold mains will allow it, as all instant hot water heaters instantly die off if not getting cold mains priority. 

 

[Carrerahill]

1 minute ago, Nickfromwales said:

Agree, but quite a lump she is ( floorstanding iirc ? )

I go for the Vaillant 938 ( wall-hung ) heat-store combi which does two adequate showers, IF the cold mains will allow it, as all instant hot water heaters instantly die off if not getting cold mains priority. 

 

She is that! She is floor standing but she isn't on the floor, there is a plint built into the house at about 800mm AFFL which it sits on as this made for easier access for maintenance etc.

 

That 938 looks pretty good and being wall-hung will make it more appealing to many.