Boiler recommendation

[JonathanM]

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.

200W has an extreme modulation ratio of 19:1. That actually puts me off, plus cost, of course.

Installer coming next week said he switched from Vaillant due to problems, He likes Alpha now. But most people have said stay clear of Alpha.

I would also like to know more about the Vogue and how it's improved over the Logic. I know it has SS heat exchanger. Logic Max already has 10 year warranty, so it's only two years better. The thing that really put me off the Logic, was the lack of options to try to maximise the chance of it running cool successfully. From what I can tell so far, there's no extra options on the Vogue, but I've only really skimmed the manual.

 

[Ltnman]

I got rid of the hot water tank years ago. The down side is the 15 second wait for hot water to appear at the tap. The advantage is that it creates more space by removing the tank from the airing cupboard, which can be replaced by a very small radiator and the fact that I am not constantly heating a tank of hot water that is not used. For my family of 4 adults we are using an average of only 2.5Kw of gas a day for hot water, at a cost of 25p. We also use an aeration shower head that injects bubble and cuts down water consumption to around 5 litres a minute without any difference noticed to shower pressure. HW and CH temperatures can be separately set for energy savings on a combi.

Just make sure you get a mini shock arrestor fitted that will protect the boiler of your choice, as most boilers these days have plastic components that water passes through, as they only cost around £20 to buy.

I didn’t buy a Viessmann as I wanted to support British manufacturing so British jobs.

 

[Ltnman]

I would also like to know more about the Vogue and how it's improved over the Logic. I know it has SS heat exchanger. Logic Max already has 10 year warranty, so it's only two years better. The thing that really put me off the Logic, was the lack of options to try to maximise the chance of it running cool successfully. From what I can tell so far, there's no extra options on the Vogue, but I've only really skimmed the manual.

For starters the Logic has just been updated so check out the Ideal YouTube channel for details. If you went for the Logic make sure you get the version you want, as both will be kicking around for a while.

The Vogue is physically a bigger boiler.
Both can use the Halo so I would stick with Ideal controls as they can modulate the boiler.
Don’t get a Hive,which can’t modulate.
Neither boiler can be range rated, which seems to be more unusual these days.
Stainless steel v aluminium heat exchanger, which is better for hard water areas.
Vogue has a more intuitive display even drawing graphs for flow and return water temperatures, which is good for making sure the boiler is condensing all the time. (New Logic has an upgraded display but might or might not be as good as the Logic is I haven’t checked)
Vogue is a premium product with a premium price but as installer costs will be the same the final bill won be that much more.

 

[Johntheo5]

The HW is now set to 42C so I don’t need to add cold

Does the primary water temperature reduce as well I wonder to maintain this temp, (and give better efficiencies, as the return temperature is colder) or is it fixed at a high level for all DHW temperatures. The same query applies to all boilers with DHW temperature control.

 

[JonathanM]

For starters the Logic has just been updated so check out the Ideal YouTube channel for details. If you went for the Logic make sure you get the version you want, as both will be kicking around for a while.

The Vogue is physically a bigger boiler.
Both can use the Halo so I would stick with Ideal controls as they can modulate the boiler.
Don’t get a Nest, which can’t modulate.
Neither boiler can be range rated, which seems to be more unusual these days.
Stainless steel v aluminium heat exchanger, which is better for hard water areas.
Vogue has a more intuitive display even drawing graphs for flow and return water temperatures, which is good for making sure the boiler is condensing all the time. (New Logic has an upgraded display but might or might not be as good as the Logic is I haven’t checked)
Vogue is a premium product with a premium price but as installer costs will be the same the final bill won be that much more.

Thank you for the info. I would definitely like to buy British, if I can find the right boiler.

Have you done some graphs for flow and return temperatures? I would be really interested to know what figures you've been getting.

EDIT: Is modulating the boiler with Halo the same as load compensation? Does it turn the burner down, or does it also adjust the flow temperature?

 

[djooms]

I got rid of the hot water tank years ago. The down side is the 15 second wait for hot water to appear at the tap. The advantage is that it creates more space by removing the tank from the airing cupboard, which can be replaced by a very small radiator and the fact that I am not constantly heating a tank of hot water that is not used. For my family of 4 adults we are using an average of only 2.5Kw of gas a day for hot water, at a cost of 25p. We also use an aeration shower head that injects bubble and cuts down water consumption to around 5 litres a minute without any difference noticed to shower pressure. HW and CH temperatures can be separately set for energy savings on a combi.

Just make sure you get a mini shock arrestor fitted that will protect the boiler of your choice, as most boilers these days have plastic components that water passes through, as they only cost around £20 to buy.

I didn’t buy a Viessmann as I wanted to support British manufacturing so British jobs.

Thanks. That's some good advice. I wanted to stick to British also. My reasoning being that it would be easy to get replacement parts. I don't think replacement parts seems to be an issue with Worcester Bosch though. I've read that the customer services are good for both, though both seem to have some negative also. After a quick look up about the mini sock arrestor, it seems to be a recommendation if the boiler is installed near a water meter, which it will be in my property. Good shout.

I know it makes sense to install a thermostat from the boiler manufacturer so they work properly together, but I haven't read much good feedback from both the Ideal and Worcester Bosch systems. Ideal is one of a few that support the Opentherm standard, so as long as the thermostat supports Opentherm, modulation should work properly. Nest does support modulation through Opentherm but Google already had enough information on me, so I don't need to give them any more.

 

[mizuno]

200W has an extreme modulation ratio of 19:1. That actually puts me off, plus cost, of course.

Why would that put you off? Surely it's a good thing. I suppose it makes the boiler more mechanically complex and with modulation like that one is quickly approaching the point of diminishing returns. The cost, obviously, I agree with.

 

[mizuno]

@djooms it is always nice to have lots of hot water, especially with two bathrooms. I am a bit biased as I did my research mostly around Viessmann. Just FYI, the Viessmann 200 series do not support OpenTherm, they rely solely on weather compensation. The 200 series is very expensive too.

If you are thinking of getting/replacing an unvented hot water cylinder, a storage combi might be an attractive option, the Viessmann 111-W works really well for me, modulation of 1:10 - https://www.viessmann.co.uk/en/products/gas/vitodens-100-w-vitodens-111-w.html
It is quite a big boiler though, but it fits fine in our airing cupboard.

Vaillant also do a storage combi, but the modulation is not as good, 1:4 if I remember correctly - https://www.vaillant.co.uk/homeowners/products/ecotec-plus-combination-store-1152.html

The other alternative might be the Intergas Xtreme series, where a flue gas heat recovery improves the hot water flow compared to other boilers of same output, great modulation of 1:9, you can read more here - https://www.intergasheating.co.uk/homeowner/products/xtreme/

 

[Ltnman]

Nest does support modulation through Opentherm but Google already had enough information on me, so I don't need to give them any more.

I meant Hive, sorry

This is worth a watch and will give you a good understanding.

 

[Ltnman]

Does the primary water temperature reduce as well I wonder to maintain this temp, (and give better efficiencies, as the return temperature is colder) or is it fixed at a high level for all DHW temperatures. The same query applies to all boilers with DHW temperature control.

My understanding after reviewing many sites is that on a combi the DHW and CH are both independently controlled and actually even have different maximum Kw outputs. When the hot tap is turned on the CH turns off. For DHW the boiler needs a high output to produce sufficient hot water so should closely match what the kitchen cold tap can supply rather then getting a boiler that can produce 17 litres of hot water a minute when the cold tap can only produce 12 litres.

 

[JonathanM]

Why would that put you off? Surely it's a good thing. I suppose it makes the boiler more mechanically complex and with modulation like that one is quickly approaching the point of diminishing returns. The cost, obviously, I agree with.

I think it is probably going to be diminishing returns. I hope the 100W, at 3.2 KW, would be as low as needed for this house, as it's pretty big. And there's a few articles saying extreme modulation is not a good idea, which have made me think.

 

[Ltnman]

Thank you for the info. I would definitely like to buy British, if I can find the right boiler.

Have you done some graphs for flow and return temperatures? I would be really interested to know what figures you've been getting.

EDIT: Is modulating the boiler with Halo the same as load compensation? Does it turn the burner down, or does it also adjust the flow temperature?

The boiler can display, via the menu, the actual flow and return temperatures. It can also plot a graph of flow, return. and flow and return together using the display.

The lower the return the better. At around 55c gives an efficiency of around 88%. At the moment my return is around 35C on a flow temperature of 50C.

Balancing the radiators to restrict water flow is key with the aim that all radiators heat up at the same rate. I have a differential of around 10C across the input and output of each radiator. The other variable is the temperature of the output of the water from the boiler. The hotter the flow the higher the return so the lower the efficiency.

 

[JonathanM]

The boiler can display, via the menu, the actual flow and return temperatures. It can also plot a graph of flow, return. and flow and return together using the display.

The lower the return the better. At around 55c gives an efficiency of around 88%. At the moment my return is around 35C on a flow temperature of 50C.

Thanks. That flow and return difference sounds really good. I'd be more than happy if I get that. Must be condensing really well.

Have you done anything extra to get it working so well, apart from the balancing?

 

[vulcancontinental]

The boiler can display, via the menu, the actual flow and return temperatures. It can also plot a graph of flow, return. and flow and return together using the display.

The lower the return the better. At around 55c gives an efficiency of around 88%. At the moment my return is around 35C on a flow temperature of 50C.

Balancing the radiators to restrict water flow is key with the aim that all radiators heat up at the same rate. I have a differential of around 10C across the input and output of each radiator. The other variable is the temperature of the output of the water from the boiler. The hotter the flow the higher the return so the lower the efficiency.

While the boiler is running could you nip out and mention whether the flue has a plume? Can your boiler show flue and return temperatures?

 

[Ltnman]

I haven’t seen a plume yet, I assume that has something to do with the return temperature and the mild weather. At the moment the heating is switched off so I can’t recheck. The boiler does not show the flue temperature but does show the return temperature In a menu which is displayed as a number or as a graph.