New boiler???

[Smiffy]

What are your reasons for choosing to go with a combi boiler?

We moved last year to a house with a combi boiler. First time we've had one. On reflection I think I prefer a traditional system with a hot water tank.

I cannot get a direct replacement for what we currently have, so a combi is being recommended by every company we talk to, including my friend Ray Taylor, who is a corgi registered heating and plumbing engineer and the one who installed our current set up twenty years ago. Unfortunately, he lives too far away to carry out the work but is advising me and has checked the quotes I have been given.
His opinion is that all of the quotes I have are very competitive, and cheaper than he could do it for
Prices all include one of those nest things....

 

[backwoodsman]

What are your reasons for choosing to go with a combi boiler?

We moved last year to a house with a combi boiler. First time we've had one. On reflection I think I prefer a traditional system with a hot water tank.

To my mind, Combi only heats the water you need, and at the time you need it. Tank has a reservoir of water - often more than you need - and needs to be kept hot. OK, modern insulation is good, but it's not perfect so tank does need constant/persistent heating.

 

[PJ87]

I cannot get a direct replacement for what we currently have, so a combi is being recommended by every company we talk to, including my friend Ray Taylor, who is a corgi registered heating and plumbing engineer and the one who installed our current set up twenty years ago. Unfortunately, he lives too far away to carry out the work but is advising for me and has checked the quotes I have been given.

What's your insulation like? Only ask because octopus are offering very cheap heat pumps due to the gov grant (think £1000 in some cases) for a house that fits a system that has a water tank etc

Might be worth looking into

https://octopus.energy/get-a-heat-p...a_mt=p&hsa_src=g&hsa_ad=671918828345&hsa_acc={6800166228}&hsa_net=adwords&hsa_kw=octopus%20heatpump&hsa_tgt=kwd-1687397902054&hsa_ver=3&gad=1&gclid=CjwKCAjwseSoBhBXEiwA9iZtxggRB22RLQwG8AuCRayDBfWr307Qs6WwLJGUtzSuYSX12sn-8_nMPxoCndwQAvD_BwE

 

[cliveb]

I cannot get a direct replacement for what we currently have, so a combi is being recommended by every company we talk to, including my friend Ray Taylor, who is a corgi registered heating and plumbing engineer and the one who installed our current set up twenty years ago. Unfortunately, he lives too far away to carry out the work but is advising me and has checked the quotes I have been given.
His opinion is that all of the quotes I have are very competitive, and cheaper than he could do it for
Prices all include one of those nest things....

Ok, but what are their reasons for recommending a combi? I'd ask for an explanation why it's better.

By the way, if I had a friend who was a plumber and he said he couldn't do the job as cheap as others, that would ring alarm bells regarding the competence of those others.

To my mind, Combi only heats the water you need, and at the time you need it. Tank has a reservoir of water - often more than you need - and needs to be kept hot. OK, modern insulation is good, but it's not perfect so tank does need constant/persistent heating.

Modern tank insulation is so good that losses are insignificant. A combi boiler with preheat switched on will waste more gas than the losses from a modern tank.

So switch off preheat (as we have done, and I believe is usually recommended). Then you have to wait quite a while for any hot water to be delivered.

Also, no option for a power shower if your water pressure isn't good.

Finally, if you lose the water tank, you lose your warm airing cupboard unless you arrange for some other form of heating in it.

 

[Smiffy]

Ok, but what are their reasons for recommending a combi? I'd ask for an explanation why it's better.

By the way, if I had a friend who was a plumber and he said he couldn't do the job as cheap as others, that would ring alarm bells regarding the competence of those others.


Modern tank insulation is so good that losses are insignificant. A combi boiler with preheat switched on will waste more gas than the losses from a modern tank.

So switch off preheat (as we have done, and I believe is usually recommended). Then you have to wait quite a while for any hot water to be delivered.

Also, no option for a power shower if your water pressure isn't good.

Finally, if you lose the water tank, you lose your warm airing cupboard unless you arrange for some other form of heating in it.

He's a friend, but his work is not cheap!!
All the quotes I have had thus far are from companies that have impeccable reviews from both checkatrade and google.
I have no qualms about using any of them.

 

[Mel Smooth]

Get one of these - great boliers.

Vitodens 050-W B0KA 25kW Combi Boiler

7968573 Vitodens 050-W B0KA 25 kW Combi

viessmanndirect.co.uk

 

[backwoodsman]

Ok, but what are their reasons for recommending a combi? I'd ask for an explanation why it's better.

By the way, if I had a friend who was a plumber and he said he couldn't do the job as cheap as others, that would ring alarm bells regarding the competence of those others.


Modern tank insulation is so good that losses are insignificant. A combi boiler with preheat switched on will waste more gas than the losses from a modern tank.

So switch off preheat (as we have done, and I believe is usually recommended). Then you have to wait quite a while for any hot water to be delivered.

Also, no option for a power shower if your water pressure isn't good.

Finally, if you lose the water tank, you lose your warm airing cupboard unless you arrange for some other form of heating in it.

If the tank doesn't lose heat, how come the airing cupboard is warm ?

 

[PJ87]

If the tank doesn't lose heat, how come the airing cupboard is warm ?

Have to admit hot water tanks are what's put me off going heat pump, I really want one but can't figure out where to put a tank! Obviously once upon a time the house had one before we owned it but now all the space used for it is taken up by living space

 

[Smiffy]

I like the idea of "instant" hot water too. Okay, there will be a very slight delay, but it won't be anywhere near the length of time it takes for the hot to come out of our kitchen tap at the moment.
Plus it's going to free up quite a bit of space and not look anywhere near as unsightly as the current cream TARDIS sitting in the kitchen...

 

[Voyager EMH]

We had a new boiler installed last year.
First morning after installation, I came downstairs and went straight to it to check all was well.
There was a message scrolling across the tiny screen, it read, "Should have bought a better boiler than this you idiot."
Then I realised what I had done.
I had bought a condescending boiler.

Thank you. Thank you for reading my pathetic joke.
Got me coat.

 

[cliveb]

If the tank doesn't lose heat, how come the airing cupboard is warm ?

Touche!

Yes, of course there is a slight loss of heat, but it's very minimal.
Enough to keep the chill off an airing cupboard, though.

 

[Smiffy]

Touche!

Yes, of course there is a slight loss of heat, but it's very minimal.
Enough to keep the chill off an airing cupboard, though.

That's why our bloody cat will try to kill us to get in there

 

[cliveb]

I like the idea of "instant" hot water too. Okay, there will be a very slight delay, but it won't be anywhere near the length of time it takes for the hot to come out of our kitchen tap at the moment.
Plus it's going to free up quite a bit of space and not look anywhere near as unsightly as the current cream TARDIS sitting in the kitchen...

We're getting down a bit of a rabbit hole here.
What I'm trying the get out of you is the reasons the plumbers have given for why a combi is better.

Regarding your comment about the length of time it takes to get hot water out of your kitchen tap...
Presumably it takes a long time to get from the existing hot water tank to the kitchen because the piping from the tank to the kitchen is fairly long?
And you're going to be putting the new combi boiler where the tank currently sits, yes?
Doesn't that mean the water will have the same amount of pipework to go through to reach the kitchen?
Since the boiler will have to fire up to heat the water, it'll probably take longer to get hot water out of the tap than it did to get the (already hot) water out of the tank.

 

[PJ87]

We're getting down a bit of a rabbit hole here.
What I'm trying the get out of you is the reasons the plumbers have given for why a combi is better.

Regarding your comment about the length of time it takes to get hot water out of your kitchen tap...
Presumably it takes a long time to get from the existing hot water tank to the kitchen because the piping from the tank to the kitchen is fairly long?
And you're going to be putting the new combi boiler where the tank currently sits, yes?
Doesn't that mean the water will have the same amount of pipework to go through to reach the kitchen?
Since the boiler will have to fire up to heat the water, it'll probably take longer to get hot water out of the tap than it did to get the (already hot) water out of the tank.

Maybe unlimited hot water is more appropriate

 

[Smiffy]

It will be hotter out of the bathroom which is right next door to the airing cupboard...

 

[Deleted member 1740]

Ok, but what are their reasons for recommending a combi? I'd ask for an explanation why it's better.

By the way, if I had a friend who was a plumber and he said he couldn't do the job as cheap as others, that would ring alarm bells regarding the competence of those others.


Modern tank insulation is so good that losses are insignificant. A combi boiler with preheat switched on will waste more gas than the losses from a modern tank.

So switch off preheat (as we have done, and I believe is usually recommended). Then you have to wait quite a while for any hot water to be delivered.

Also, no option for a power shower if your water pressure isn't good.

Finally, if you lose the water tank, you lose your warm airing cupboard unless you arrange for some other form of heating in it.

The most obvious reason to convert to a combi installation is costs of heating stored water vs use of that heated water.

At the minute smiffy is heating 150ltrs of water for potentially 2 showers of a morning and maybe washing breakfast dishes for 2 people.

To heat a tank that usualy takes 30-40minutes to heat fully. Its a waste of energy.

 

[jim8flog]

What are your reasons for choosing to go with a combi boiler?

We moved last year to a house with a combi boiler. First time we've had one. On reflection I think I prefer a traditional system with a hot water tank.

I know for me it was simple.

One was cost. To get a modern tank it would need to be be bought in the first place basic tank is around £ 300 plus additional cost of fitting

I have not had a bath for over 30years and use an electric shower.

Ability to control hot water temperature whilst stood at the kitchen sink. For washing up around 50 degrees is ample, even slightly too hot. The water in a storage tank needs to heated to 70 degree to kill bacteria as it is stored.

I am only heating the water I actually need - enough to wash up every other day, fill the kettle with hot water (something that cannot be done with tank stored water) small amount in bathroom basin for washing and once a week car wash. So an average of a few litres a day. With a tank you are heating up over a 100 litres of water every time, probably twice a day.

The only downside is that I cannot have a power shower which is something that bothered my daughter when she was living with me and the occasional visitors but not me.

 

[cliveb]

People seem to be labouring under the impression that once you heat the water in a tank it needs to be used straight away before it gets cold.
Not true. As I said before, modern tanks are so well insulated that losses are minimal. In the year we've been in the house with a combi boiler, we haven't noticed a reduction in gas usage compared to the previous house that had a standard condensing boiler.

Jim makes a good point about being able to reduce the temperature of the water. Hadn't thought of that one.

 

[Bunkermagnet]

We went from an indirect heating system and boiler to a combi boiler system. Granted our cold water pressure is normally pretty good, but our gas usage is now a third of what we used to have. That is the only gas appliance we have.

 

[Robster59]

Just an observation on moving to a combi-boiler. We did this at our last house. The reason being was that the old boiler was over 20 years old and you couldn't get any replacement parts for it when it failed. We were recommended a combi-boiler as it would be cheaper to run. It was an Alpha but I can't comment on how good it is against alternate brands as I haven't had them.

But... The combi pumped water at a higher pressure than our old boiler with hot water tank in the attic. The result of this is that if you have old pipwork that has any potential issues then it will hunt them out. We developed a leak in our old pipework as a result of this and had to have it repaired which involved taking part of the wall out to reach the damaged pipe. A real mess.

I'm not sure what the mains water pressure is like here, but we have a water pump under the sink in our new house that comes on every time we turn any taps on, or flush the toilet, so I am guessing it is pretty low.

I would consider a heat pump but I read somewhere (may have been on here) that you need larger radiators and large bore tubing.

EDIT: I just went on to the Octopus site and clicked on their "Get a Quote" option and got this.

"Thanks so much for your interest in a heat pump.

Unfortunately, based on the details you've given us, it looks like your home isn't a fit for a heat pump at the moment. We look at a number of factors including your home's size, location, and heat loss to make this determination. The available information tells us a heat pump isn't quite right for you today.

But we're innovating fast at our green heating research & development centre on new solutions that will work for your home. Once we've found the right one, we'll get back in touch."