alpha etec boiler?

Albermarle

When I changed from a non condensing boiler ( from 1994) to a condensing one about 7 years ago, it saved about 15% on gas consumption.
Same timer, radiators, TRV's etc . I have kept the flow temperature down to max 60 most of the time. 65 in very cold weather.

Steveotwo

@Eldi_Dos
Hey, im just anxious after moving from our last place with a greenstar combi, super efficient super low bills to this system that heats up a full tank of water for half a sink of hot water. it just causing my anxiety about how it may effect our bills month to month. old boiler is a baxi solo from 2004

Albermarle

You do not need to heat the whole tank just to get half a sink of hot water, or even for a couple of showers for that matter. You can restrict the hot water heating time with the timer, to suit your needs.
Also modern hot water tanks are very well insulated.

Eldi_Dos

@Steveotwo

If you are concerned about your energy usage post up details about the type of controls you have on your system at the moment,and how you run your heating system.There will be good advice on ways that things can be improved.

If you have details of monthly usage that would help.

ThisIsWeird

Steveotwo said:

@BarelySentientAI
so what would you do just wait until the old system kicks the bucket then replace?

In essence, yes.

If it's still working, then the most cost-effective way forward is to keep it running until it breaks down properly! That way you get to keep ~£3k in your pocket; that is many years of slight energy improvement/payback time that any new boiler would give you.

Meanwhile, explore the options. 'Eco' systems are improving all the time, and dropping in price - fair chance that will continue to be the case.

If your current system actually performs fine - plenty of DHW flow, for instance - then an alternative to your combi could be a smaller, fast-recovery DHWCylinder, and a replacement for your Heat-Only boiler (tho' worth considering 'system' to get rid of the small F&E tank in the loft).

A H-O boiler will almost certainly be far more reliable than a combi. It'll be far cheaper to instal. A small DHWC will likely provide you with more hot flow than a combi, and probably from more than one outlet at a time. It'll also have electric back-up in the form of an immersion heater. If you go even partially 'green' - eg fit a few PV panels - then that will provide most of your DHW, so way cheaper than a combi.

The plumber who gave you that great combi quote, what would they charge for a H-O boiler and new, smaller, DHWC?

But, the MSE way is to stall as long as possible!

Albermarle

If your current system actually performs fine - plenty of DHW flow, for instance - then an alternative to your combi could be a smaller, fast-recovery DHWCylinder, and a replacement for your Heat-Only boiler (tho' worth considering 'system' to get rid of the small F&E tank in the loft).

If they changed to a system boiler - so an unvented system running direct off the mains, would that not mean quite a bit of extra costs as an unvented HW tank would have to be fitted with all the extra pipework/safety valves etc ?

A H-O boiler will almost certainly be far more reliable than a combi

Is that actually a widely accepted fact ? Just interested.

Steveotwo

@Albermarle
So are you saying that if i use a timer or just turn it on on a morning or evening, I wouldnt see much of a difference switching to combi using it in this way?

Steveotwo

@Eldi_Dos
Hey before moving my estimated consumption of gas was £460.07  estimated annual usage was 6395 kWh with my greenstar 4000 30kw combi

In my new house I haven't had a bill yet, its a baxi solo system boiler from 2004 I have a Drayton lp522 controller on the wall. No header tank just a water tank with green foam insulation around it. 

Albermarle

Steveotwo said:

@Albermarle
So are you saying that if i use a timer or just turn it on on a morning or evening, I wouldnt see much of a difference switching to combi using it in this way?

I can not make an exact comparison, but was just making the point that you do not need to heat the whole tank if not necessary. 
For example in our house with two showers in the morning and a bath in the evening( not all for me) + a bit of other hot water usage, the hot water is on for 30 mins in the morning and 15 mins later. Maybe could even be a bit less but I do not want the family complaining if the water is not quite hot enough.
With a modern hot water tank you can hardly feel it is warm if you put your hand next to it as they are so well insulated.

FreeBear

Albermarle said: A H-O boiler will almost certainly be far more reliable than a combi

Is that actually a widely accepted fact ? Just interested.

No P2P heat exchanger to get clogged up. No diverter valve to get stuck (although there will be a zone valve or two, hopefully external). Fewer sensors to go faulty, and hopefully, a simpler main control PCB.

So a heat only boiler is potentially more reliable due to the reduction of components inside.