New Gas Boiler

BUFF

Zandoni said:

BUFF said:

It was well known as bus control before Opentherm came along as an independent rather than proprietary variant. The original Opentherm specification was sold to the association by Honeywell.
Vaillant have proprietary e-Bus, Viessmann have K-Bus, Bosch Group have EMS & there are even manufacturers that have taken advantage of flexibility in Opentherm specification to make it more difficult for Opentherm devices from 3rd-party suppliers to run with their Opentherm boilers.

The heating industry generally seems to  to line up behind the reasons why a boiler running lower for longer is better for boiler & system life but you are allowed to have your own opinion.
 
Yes, I did say that "a new boiler+new controls all properly set up & used might" (not will).
Also note. not "new boiler" but "new boiler+new controls". I also said "it depends where you are coming from to start".
My last  "new boiler+new controls" change demonstrably has paid for itself over it's 13 years (14 heating seasons) which I attribute roughly 50% to generational (non-condensing balanced flue> condensing fan-flued) boiler efficiency savings  & 50% to efficiencies gained from using improved controls. However, and for the 3rd time now, I am also saying that I don't expect the next boiler+controls change to achieve that - the easy gains have been made & there is very limited room for improvement over what I currently have.

I'll leave you with your opinion but mine hasn't changed, I still think you should only change your boiler when it dies.

& I sttill don't get why you don't think that is the plan?
That is what I did last time (when the boiler required an uneonomic repair) & I have already said " I am planning on upgrading the controls when I next have to replace my boiler. "
For clarification, imo "dies" also includes the need for an uneconomic repair.

Zandoni

BUFF said:

Zandoni said:

BUFF said:

It was well known as bus control before Opentherm came along as an independent rather than proprietary variant. The original Opentherm specification was sold to the association by Honeywell.
Vaillant have proprietary e-Bus, Viessmann have K-Bus, Bosch Group have EMS & there are even manufacturers that have taken advantage of flexibility in Opentherm specification to make it more difficult for Opentherm devices from 3rd-party suppliers to run with their Opentherm boilers.

The heating industry generally seems to  to line up behind the reasons why a boiler running lower for longer is better for boiler & system life but you are allowed to have your own opinion.
 
Yes, I did say that "a new boiler+new controls all properly set up & used might" (not will).
Also note. not "new boiler" but "new boiler+new controls". I also said "it depends where you are coming from to start".
My last  "new boiler+new controls" change demonstrably has paid for itself over it's 13 years (14 heating seasons) which I attribute roughly 50% to generational (non-condensing balanced flue> condensing fan-flued) boiler efficiency savings  & 50% to efficiencies gained from using improved controls. However, and for the 3rd time now, I am also saying that I don't expect the next boiler+controls change to achieve that - the easy gains have been made & there is very limited room for improvement over what I currently have.

I'll leave you with your opinion but mine hasn't changed, I still think you should only change your boiler when it dies.

& I sttill don't get why you don't think that is the plan?
That is what I did last time (when the boiler required an uneonomic repair) & I have already said " I am planning on upgrading the controls when I next have to replace my boiler. "
For clarification, imo "dies" also includes the need for an uneconomic repair.

No I thought your plan is fine if the boiler is on its way out, I was really saying that I don’t think it’s economical to replace a good working boiler to save gas.

markin

Brewer21 said:

We had a new boiler fitted 5 years ago, a condensing Worcester Bosch. It replaced s 24 year old Worcester combi boiler. Sited in exactly the place, virtually a straight swap. I've also had the radiators upgraded (newer) over the last 5 years too. Whilst I was expecting a small improvement in gas consumption (using less) it hasn't really happened, perhaps in a minor way. What we do have is a noteably warmer home for winter, hotter water when drawn off. 
The old boiler used to chug along making all kinds of noises and took an age to heat up the home and heat the water to something that passed as hot.

So looking at our usage over many years including with the old boiler, it's all logged down in a book (readings taken weekly and still do) we can't really say we saved on gas/electric over the years, marginally I'd say. We get more bang for our bucks though.
So really don't expect to save any fantastic amounts monetary wise when fitting a new boiler, it'll do the job better so to speak.

Was it like for like in KW rating? Most people wouldn't remember the rating after 24years.

seatbeltnoob

dont go combi, you'll regret it. stick to a system boiler.

you'll have to run the tap for 30 seconds to get hot water, and in cold winter mornings, it's agonising. if you are in the shower and someone runs the hot water taps anywhere in the house you'll get cut out of hot water.

combi boilers have issues every few years, 2 years ago divertor valve went, this year pcb went.

good thing with combis though is that central heating comes on fast. within 5 minutes the radiators all over the house are piping hot.

Reed_Richards

I inherited a combi boiler with the same issue, a huge wait to get any hot water out of a hot tap.  If you do install a combi you must pay close attention to how the pipes are routed and ensure all the pipe runs are as short as possible.    

victor2

Reed_Richards said:

I inherited a combi boiler with the same issue, a huge wait to get any hot water out of a hot tap.  If you do install a combi you must pay close attention to how the pipes are routed and ensure all the pipe runs are as short as possible.    

Good advice - we replaced our old boiler and hot water tank with a combi last year. Even though the boiler is close to the kitchen, the hot water feed to the kitchen sink goes upstairs to where the hot water tank was, then down to the kitchen from there. Takes forever to get warm!
Would be a major job to neatly run new pipes, but wish I'd been aware of the issue before it was installed.

Magnitio

Hot water cylinders will typically lose between 1 and 2 kWh of heat every day, even those that are very well insulated. At 7p per kWh, that's £25 to £50 per annum. There are also inefficiencies in heating that water from the boiler. Replacing an old 75% efficient boiler with a 90+% efficient boiler could easily save a further £200 a year for heating a typical house. With the increasing gas prices, the savings will be even greater. There is also a significant environmental benefit of using less gas, as well as political if we can reduce our imports.

Section62

Magnitio said:

Hot water cylinders will typically lose between 1 and 2 kWh of heat every day, even those that are very well insulated. At 7p per kWh, that's £25 to £50 per annum. There are also inefficiencies in heating that water from the boiler. Replacing an old 75% efficient boiler with a 90+% efficient boiler could easily save a further £200 a year for heating a typical house. With the increasing gas prices, the savings will be even greater. There is also a significant environmental benefit of using less gas, as well as political if we can reduce our imports.

But see victor2's post immediately before yours.  If a combi is not installed with the pipework optimised then there will be a volume of water wasted each time a hot tap is turned on when the water in the pipe has cooled.  If the property has a water meter (which more and more of us will have going forward) then you need to factor the cost of wasted water into the equation as well.

Rearranging the hot water distribution pipework to make it more efficient is an option, but it would be easy to spend 10 year's worth of energy savings (in the £25 to £50pa range) getting a plumber to do this.

And then when we are no longer able to buy gas combi boilers most of us will be looking at installing some form of hot water storage tank.  Again, for most the optimum place for that future hot water storage tank is likely to be where the existing or previous one is/was.  Necessitating another reorganisation of the hot water distribution system if it has been altered to suit a combi.

There are many factors other than the current price of gas which need to be taken into consideration.  Personally, I would increase the insulation on the hot water cylinder, and otherwise make the minimum alterations necessary until there's a clearer picture of what future domestic heating is going to consist of.

Reed_Richards

Section62 said:

But see victor2's post immediately before yours.  If a combi is not installed with the pipework optimised then there will be a volume of water wasted each time a hot tap is turned on when the water in the pipe has cooled.  

I calculated that I wasted an extra 0.7 kWh every time I ran a hot tap then allowed the water trapped in the pipes to cool.  This was based on 15 l of water trapped in the pipes after being heated by 40 C in the boiler.  I know it was about 15 l because I had to run-off a bucket and a half of cold water before the hot tap ran hot.

matelodave

I end up wasting around 5 litres between my hot water tank and the bathroom tap to get hot water so I do try to use cold whenever possible (although I do draw the line at shaving or showering with cold water)

Unfortunately I can't persuade my wife to stop rinsing stuff, including her hands or even yoghurt pots without running off five litres down the drain and then leaving another five to sit in the plumbing to get cold until the next time.