Intergas HRE36/40 or RFC36

[creative101]

Need a replacement combi for a 4 bed / 2 shower and was looking at the Intergas HRE36/40 and RFC36.

Seen many people recommend the RFC36 but not sure it will be enough for a 4 bed / 2 shower house. Unfortunely a tank isnt an option due to space. Any recommendations?

Intergas HRE 36/40
41kw
13-18 DHW

Intergas ECO RF 36
27kw
13-18 DHW

 

[muggles]

The 40 in 36/40 relates to the heat output to central heating, not to hot water. It is exactly the same hot water power as the ECO RF 36 (or indeed the HRE 36/30). Combi boilers in general are only really suited to running one shower at a time unless you install flow restrictors. Is there really no space anywhere for even a small cylinder, even in the loft? You may find that you either need to compromise on space, or compromise on hot water performance.

 

[creative101]

The reason for going for the 36/40 is purely to get heat to the radiators which are spread across three floors and wasnt sure it was worth compromising by going with 36/30.
Re a small cylinder, can one be fitted to the 36/40? If so, any suggestions?

 

[muggles]

Do you have space for a 125L Joule High Gain? That should give you plenty of hot water when coupled to a 36/40 (or 40SB) at a higher flow rate than any combi will deliver (assuming your incoming mains can keep up of course). Needs to be installed in a hot water priority configuration to work, but that's easy enough to do.

Boilers aren't sized based on how many floors you have, or how far the water has to travel. They're sized based on how much heat the property and, where applicable, the hot water cylinder requires. Do a heat loss calculation and you'll be surprised just how little heat you need! Combi boilers and boilers running modern hot water priority systems tend to be oversized for central heating to keep up with hot water demand, but if you're going for a straight combi then I'd be very surprised if you need as much as 30kW for central heating

 

[creative101]

With no real price difference between the hre36/40 and 40sb, wondering it makes sense to go for the hre36/40 now and if required at a later date (and if im able to find space somewhere) to add the cylinder later.... ??

 

[muggles]

Yes, that's certainly an option

 

[creative101]

Just came across the xclusive36. Anyone know what the difference is between this and the hre30/40? With the hre36/40 seems you have to buy a fitting kit which brings the price equal.
Which one should I got for?

 

[hard-work]

I know an Intergas 36/30 that is fitted with two showers. The shower heads were the eco Raindance aerated models made by Hansgrohe. The Raindance mixes air with the water meaning is uses less water for the same effect as high flow shower heads - around 9 litres per minute after being mixed with hot and cold water, so hot water draw off is even less than 9 litres/min.

I inquired whether they have used the two showers together, they had however only on rare occasions. When they did, the combi coped. If I was you I would go down this route - ensure you do not draw off high water flows in showers.

Or to be sure, fit a higher output quality Navien (biggest combi boiler makers in the world). 40kW the NCB-40LSWE. It delivers around 16 litres/minute of hot water. They are well priced and well specced for sure.

There is no need to install a cylinder when running only two showers, when quality high output combis are around

I hope this helps.

 

[hard-work]

The new Intergas Xtreme and Xcusive combis; one has a higher hot water rate by around a litre per minute over the best of the rest. So worth considering. The new Intergas combis have better electronic control and user interface than the older models.

 

[hard-work]

Combi boilers and boilers running modern hot water priority systems tend to be oversized for central heating to keep up with hot water demand

They modulate down when running CH, so the high kW figure is not a problem (many plumbers get confused on this, heating engineers do not, not saying you do). With many combis you can cap the maximum kW when running CH, allowing only the maxium (say 40kW) output when running DHW, which also modulates.

 

[wizbongre]

We're about 1.5months in to our new Intergas Xclusive 36. We only have 1 shower at the moment, however its a big rain-shower type head. With 2 adults and 2 young children, its pretty common for the shower to be running at the same time as "something" else, such as dishwasher, washing machine, taps, etc. Maybe our expectations were low as we had a very poorly Glowworm 30Cxi previously but the water flow, pressure and temperature with the new Intergas is brilliant. Filling a bath full of hot water takes no time at all. The other unexpected bonus is that when the heating is running, the Xclusive is very quiet, both in terms of the boiler itself and the system around the house. Again, with the old Glowworm, we could hear the water rushing around the system I suspect because the pump on it had no speed adjustment and all of our radiator tails are 10mm - too much flow into too little pipework.

I ended up requesting the Intergas after years of reading about them on here and whilst it is very early, I'm more than pleased.

 

[creative101]

Hre36/40 specs:
https://www.intergasheating.co.uk/specifier/products/hre/hre-36-40/

xclusive36 specs:
https://www.intergasheating.co.uk/specifier/products/xclusive/xclusive-36/technical-data/

Is the hre36/40 a better spec than the xclusive36 or am I not reading the specs right?

 

[creative101]

We're about 1.5months in to our new Intergas Xclusive 36. We only have 1 shower at the moment, however its a big rain-shower type head. With 2 adults and 2 young children, its pretty common for the shower to be running at the same time as "something" else, such as dishwasher, washing machine, taps, etc. Maybe our expectations were low as we had a very poorly Glowworm 30Cxi previously but the water flow, pressure and temperature with the new Intergas is brilliant. Filling a bath full of hot water takes no time at all. The other unexpected bonus is that when the heating is running, the Xclusive is very quiet, both in terms of the boiler itself and the system around the house. Again, with the old Glowworm, we could hear the water rushing around the system I suspect because the pump on it had no speed adjustment and all of our radiator tails are 10mm - too much flow into too little pipework.

I ended up requesting the Intergas after years of reading about them on here and whilst it is very early, I'm more than pleased.

really helpful to know. Thanks.

 

[Mr.B]

Must admit I'm edging closer and closer to one of these ... that is the 36 Xclusive.

Somewhat useful to see the above "in the flesh" report. Ta muchly.

I've started to make provsion by way of a new 28mm gas supply plus a new 4 bar, 30 litres per minute 22m cold supply straight from the blue 25mm MDPE - both solely dedicated, and terminating right next to the boiler - so find wizbongre's advice reassuring.

 

[creative101]

I guess we’d be happy or none the wiser if any one of these were installed . Just looking for some comfort in buying one over the other.