Combi Boiler Modulation with Genius Hub TRV's

[Andrew Westrope]

I currently have a 17 year old Ariston Microgenus 27MFFI boiler that is getting increasingly noisy so looking to replace rather than spend money on. It supports my DHW requirements with regard to a decent shower but I don't want to go less. I have found online that it will produce 35 degree increase with a flow of 11.4L/min. This seems high compared to modern boilers of a similar size?

I have 7 rads all with TRV's controlled using the Genius Hub (was Heat Genius) system. I live on my own so tend to just heat where ever I am so the heating demand is often quite small.

My logic translates this to needing a boiler that will modulate as low as possible. Also having a bypass system that is quiet and reliable.

To my questions:

1. Is my logic correct re modulation and bypass?
2. Is the DHW flow rate of the Ariston correct?
3. Which boilers have the largest modulation?

Thanks for any help.

 

[sammathias]

most modern condensing boilers are fitted with an auto bypass inside the boiler.

the ariston flowrate is correct, say a new vaillant or glowworm can modulate to as low as 5 or 4kw but the heating load can also be adjusted upon set up. also I believe say a glowworm energy 25kw is 11.5l at 30c rise.

 

[ShaunCorbs]

Agree with the above but I would still have an external bypass fitted or a heat leak rad in the bathroom

And also have a look at Viessmann either 100w or 200w

 

[Andrew Westrope]

I have been recommended an Alpha Intec 2 28kW (modulates down to 3.5kW, DHW flow 11.7) by an engineer who I have used before for new rads and he installed a WB at my sisters recently that went well. Any comments on that boiler?

 

[ShaunCorbs]

Lower end boiler but ok

 

[Andrew Westrope]

Been quoted £325 more for Ideal Vogue 26 than Intec2 28. I expect to keep the house for the life of this boiler. Which would you choose?

 

[Andrew Westrope]

Been quoted £325 more for Ideal Vogue 26 than Intec2 28. I expect to keep the house for the life of this boiler. Which would you choose?

 

[Harvest Fields]

I have been recommended an Alpha Intec 2 28kW (modulates down to 3.5kW, DHW flow 11.7) by an engineer who I have used before for new rads and he installed a WB at my sisters recently that went well. Any comments on that boiler?

Why has he recommended you an Alpha but your sister a WB?

 

[Andrew Westrope]

WB don’t do anything that modulates low enough for me.

 

[Chalked]

Why are you being so obsessed with modulation? Which in the right situation, will save you a few ££ a year. When a decent make of boiler, will save you a lot more in the long run.
Ps, I hate both of your options and would fit a vaillant.

 

[Gasmk1]

fit a vaillant with their controls

 

[Andrew Westrope]

Why are you being so obsessed with modulation? Which in the right situation, will save you a few ££ a year. When a decent make of boiler, will save you a lot more in the long run.
Ps, I hate both of your options and would fit a vaillant.

It’s not really about the money, it’s more about having a boiler that is designed to be used in my situation and won’t be cycling constantly.

The Vaillant iQ green range has good modulation but only goes down to 35kW which is massive overkill and £1500 for just the boiler

Of the ‘decent’ makes of boiler the Viessmann is the only one with decent modulation but I can’t seem to get anyone to quote me for one of those!

 

[Andrew Westrope]

fit a vaillant with their controls

What do the Vaillant controls offer over the Genius Hub ones?

 

[Gasmk1]

probably cost just priced up my apartment 7 rads £946.00

 

[Gasmk1]

we have installed a few of them now and the wireless one i never know the numbers my mate orders them i just wire them last job was 2 heating circuits and 1 unvented with weather compensation.

the viessmann is still the best weather compensation but you should insatll the 200 boiler controls are far superior to the 100.

wherabouts are you

 

[Gasmk1]

i see you already have the genius system so that custs costs. i would go for the vissmann if you can

 

[Andrew Westrope]

we have installed a few of them now and the wireless one i never know the numbers my mate orders them i just wire them last job was 2 heating circuits and 1 unvented with weather compensation.

the viessmann is still the best weather compensation but you should insatll the 200 boiler controls are far superior to the 100.

wherabouts are you

I’m in the midlands near Leamington Spa

 

[Andrew Westrope]

i see you already have the genius system so that custs costs. i would go for the vissmann if you can

I am been warned off Viessmann due to difficulty/delay getting parts.

 

[Andrew Westrope]

Latest engineer recommending Intergas HRE 28/24 but only modulates down to 7.7kW.

It seems I either need to accept if I want a ‘premium’ boiler it will only modulate down to 7-8kW or go with the Ideal Vogue with 3-4kW minimum and trust the 10 year warantee will be stood by.

 

[ShaunCorbs]

Ideal accept there own warrenty

Have a look at Viessmann direct for spares

 

[Gasmk1]

what delay getting parts its just the guys quoting dont like them think the 200 modulates down to 3 kw