Boiler recommendation

[djooms]

Hi,

New to the forums and have registered as I can't seem to find an answer to my query.

I have a1970s detached 4 bedroom house with 2 bathrooms. We are completely renovating the property and modernising it as most of the systems installed are nearly 40-50 years old. The property originally had a system boiler with a tank in the upstairs bathroom. This has now been removed to make place for a shower, so the property will now have an upstairs bathroom with a bath and a shower and a downstairs bathroom with a shower.

Our builder has suggested installing a Worcester Bosch Greenstar 8000 range combi boiler but has said we need to decide on the capacity; either 30kW or 35kW. After a bit of research I have come to the conclusion that the capacity should be based on how much water you intend to use and not the number of radiators (there will be 13 radiators total). I doubt we will be running both showers at the same time and less likely to run a bath and shower at the same time. I am intending to put a Drayton Wiser smart thermostat as part of the install, but from my understanding this will not have the Worcester Bosch boiler running at its best efficiency using modulation as they don't support the Opentherm standard which I believe most smart thermostats use. Worcester Bosch use their own EMS standard and you need to use their own thermostats to get the most out of it.

I have also come across suggestions for the Ideal Vogue Max boilers as an alternative, but can't find much information on how good it is compared to other brands. I just wanted some advise on whether the Ideal boiler is a good option as an alternative to the Worcester Bosch and whether modulation will make a big difference to bills. I have seen Viessmann boilers as another alternative, but budget has a lot to do with the choices.

Also, what would be recommendations for capacity based on our needs? The property is getting new pipes installed throughout as part of the renovation.

Thanks in advance.

Ooma

 

[amcluesent]

With two bathrooms/showers I'd still consider a Priority Domestic Hot Water (PDHW). Sadly, too many installers can't move-on from S-plan or Y-plan designs!

Usually you'll get a longer warranty using the manufactures own controls and you definitely need weather compensation.

>I have come to the conclusion that the capacity should be based on how much water you intend to use and not the number of radiators <

Err no, the capacity should be based on expected heat loss from the house when it -2°C outside. That's a calculation that needs assessment of property size, how well insulated and size and type of windows.

You should also calculate the size of rads based on a flow temp of 55°C, the heat loss expected from the room and achieving Delta-T of more than 15°C on flow and return temps. Also as you've got a clean slate, consider under-floor in the ground floor as it's a better options than rads.

>The property is getting new pipes installed throughout <

You should go for 22mm as that would allow use of a heat pump in the future.

>Our builder has suggested...<

Best speak with an heating specialist, builders may not be up-to-date with current thinking on heating for CH and DHW.

 

[fixitflav]

With two bathrooms/showers I'd still consider a Priority Domestic Hot Water (PDHW). Sadly, too many installers can't move-on from S-plan or Y-plan designs!

If you had a W-plan you'd have PDHW free gratis and for nothing!

 

[JonathanM]

The property originally had a system boiler with a tank in the upstairs bathroom. This has now been removed to make place for a shower, so the property will now have an upstairs bathroom with a bath and a shower and a downstairs bathroom with a shower.

Just to check, as it is vital to determine what type of boiler you need. When you say you have removed the tank, do you mean that you have removed the hot water cylinder, which used to store the hot water?

 

[JonathanM]

Duplicate post - deleted - apols

 

[fixitflav]

The property originally had a system boiler with a tank in the upstairs bathroom. This has now been removed to make place for a shower, so the property will now have an upstairs bathroom with a bath and a shower and a downstairs bathroom with a shower.

What boiler do you have at the moment?

 

[djooms]

Hi,

Thanks for the suggestions and correcting of my assumptions.

Unfortunately, the renovation work is too far gone now to change the heating system, without major rework. You are most likely correct in the assumption of the builder maybe not being up to date with heating systems. I can try and ask the builder about changing things, but I highly doubt they will want to do that at the current stage of work.

Based on the assumption that I have to stick to a combi boiler, could I maybe get some suggestions for boiler brand and model and the capacity needed whilst using a Drayton Wiser thermostat? Budget is a key factor as most of our funds went into purchasing the property, so changing things now may not be financially viable either. I don't want to go for completely budget brand/model, but then also don't want to spend more than is necessary.

Thanks in advance.

Ooms

 

[djooms]

Just to check, as it is vital to determine what type of boiler you need. When you say you have removed the tank, do you mean that you have removed the hot water cylinder, which used to store the hot water?

Yes, sorry. Meant hot water cylinder.

What boiler do you have at the moment?

The old boiler has already been removed but I believe it was either a Baxi Boston OF or Boston 2. Can't really check it now as it's been disposed of. Best I've got is a screenshot from a video. I don't have any pictures unfortunately.

 

[fixitflav]

The old boiler has already been removed but I believe it was either a Baxi Boston OF or Boston 2. Can't really check it now as it's been disposed of. Best I've got is a screenshot from a video. I don't have any pictures unfortunately.

OK thanks, just curious. Personally I'm not keen on combis but it seems you've burnt your boats on that score

 

[JonathanM]

I'm looking at boiler brands as well.

It's a total minefield. There's just so much information and so many opinions.

The safe options which everyone knows seem to be Worcester Bosch, Ideal and Viessmann.

This is not a recommendation, just a suggestion. I'm currently checking out a couple of big Italian brands who sell their boilers in the UK under different brand names, Alpha, who are owned by Immergas, and Vokera who are owned by Riello. A poster on here, vulcancontinental, provides lots of great info about Vokera, as he works with them.

I've most recently been looking at Alpha. They seem to be similar price as Ideal Logic, but you get lots more configuration options. They all seem to have stainless steel heat exchangers., which some people think work better in the long run than aluminium ones - but getting accurate info on that particular point seems impossible. And a pump with lots of speed options. No idea how they compare to Vokera.

Ideal Logic boilers seem to be very much fit and forget, with very few options, unless I've missed stuff in the manual. I don't think you can even range rate them. One poster said the pump goes so fast it's hard to get the return temperature low enough to condense. Don't know about Ideal Vogue, but I'm sure a post on here said they can't be range rated.

Other high end boilers are Vaillant (German) and Intergas (Dutch).

 

[JonathanM]

Do you have a garage to put a how water cylinder in?

 

[djooms]

I'm looking at boiler brands as well.

It's a total minefield. There's just so much information and opinions.

The safe options which everyone knows seem to be Worcester Bosch, Ideal and Viessmann.

This is not a recommendation, just a suggestion. I'm currently checking out a couple of big Italian brands who sell their boilers in the UK under different brand names, Alpha, who are owned by Immergas, and Vokera who are owned by Riello. A poster on here, vulcancontinental, provides lots of great info about Vokera, as he works with them.

I've most recently been looking at Alpha. They seem to be similar price as Ideal Logic, but you get lots more configuration options. They all seem to have stainless steel heat exchangers., which some people think work better in the long run - but getting accurate info on that particular point seems impossible. And a pump with lots of speed options. No idea how they compare to Vokera.

Ideal Logic boilers seem to be very much fit and forget, with very few options, unless I've missed stuff in the manual. I don't think you can even range rate them. One poster said they pump goes so fast it's hard to get the return temperature low enough to condense. Don't know about Ideal Vogue, but I'm sure a post on here said they can't be range rated.

Other high end boilers are Vaillant (German) and Intergas (Dutch).

There is a lot of information out there and a lot of misinformation too. Like you, I keep seeing Worcester Bosch, Vaillant and Viessmann being mentioned. I'm not sure if it's a case of living off past reputation and people assuming the German stuff is the best. My parents have a high end Vaillant combi and even with servicing it annually, they've had no end of issues with the boiler. Viessmann stuff seems to be even higher priced compared to the others. I've also read that that the 200W range is the only good option and the only model they sell in Germany

I've read, the Ideal Vogue is in a completely different class to the Logic range. There's loads of info on the Logic stuff but trying to find anything on the Vogue seems to be scarce. The fact they offer 12 years warranty suggests that they are either that confident in how good the boiler is or that they know it isn't good and they are covering themselves. Again, can't find much info to get clarity on this.

A lot of the stuff I've read seems to suggest staying away from the Italian boilers, but again, I don't know if that's just misinformation again. There seems to be a lot of favouritism for certain brands, similar to car brands.

The builder's logic for Worcester Bosch is that the council put them in their rental properties. Seems a bit far fetched if you ask me. Can't really see a council going with an apparently higher end brand over a budget classed brand, but I could be wrong.

Do you have a garage to put a how water cylinder in?

No garage unfortunately. It was converted into a snug by the previous owners. We are still keeping the snug, though part of it has now been taken up to put a small utility room, which is where we are intending to put the combi boiler. It's made the snug quite small now, though it should still be of some use.

 

[muggles]

As above, you'd really be much better off having a hot water cylinder, but it seems you may have gone too far down the road of bad builders advice to do that now. Good tip for the future - ask builders about building and heating engineers about heating. As for combi boiler power, there's no point having a boiler which is more powerful than your mains water supply can handle, so firstly you need to know the flow rate and working pressure of your incoming mains. You can then determine which power boiler might be suitable for your hot water. All combi boilers will easily run your heating system from a power point of view.

As for which boiler specifically, have a look at the Intergas Xclusive and the Vokera Unica Max

 

[Ltnman]

I have just had installed a top of the range Ideal Vogue. One of the reasons I went for that model and not a Worcester was that the Vogue had a stainless steel heat exchanger and not the cheaper aluminium. I had it installed with a Wi-Fi enabled Ideal Halo that will modulate the boiler wirelessly. I was thinking that the Wi-Fi version might be a gimmick but now I have used it there is no going back. The downside of the Vogue is that it can’t be range rated but I can live with that. The HW is now set to 42C so I don’t need to add cold and the CH is running at 50C for the autumn. Any adjustments to timing patterns and room temperatures can be done via the phone.

 

[djooms]

As above, you'd really be much better off having a hot water cylinder, but it seems you may have gone too far down the road of bad builders advice to do that now. Good tip for the future - ask builders about building and heating engineers about heating. As for combi boiler power, there's no point having a boiler which is more powerful than your mains water supply can handle, so firstly you need to know the flow rate and working pressure of your incoming mains. You can then determine which power boiler might be suitable for your hot water. All combi boilers will easily run your heating system from a power point of view.

As for which boiler specifically, have a look at the Intergas Xclusive and the Vokera Unica Max

Thanks. I suppose something to learn for the next property. If it was maybe a bit earlier in the renovation, I could have changed it. I assume with Intergas being Dutch, it will probably natively support the Opentherm standard. I'll take a look at both the suggested boilers. I'll need to find out about the main water flow rate.

I have just had installed a top of the range Ideal Vogue. One of the reasons I went for that model and not a Worcester was that the Vogue had a stainless steel heat exchanger and not the cheaper aluminium. I had it installed with a Wi-Fi enabled Ideal Halo that will modulate the boiler wirelessly. I was thinking that the Wi-Fi version might be a gimmick but now I have used it there is no going back. The downside of the Vogue is that it can’t be range rated but I can live with that. The HW is now set to 42C so I don’t need to add cold and the CH is running at 50C for the autumn. Any adjustments to timing patterns and room temperatures can be done via the phone.

Thanks for this. Finally some information on why someone chose Ideal over Worcester Bosch. Much appreciated.