I'm and architect and have a Gloworm Ultimate 120FF which has worked reasonably well for 9 years but I've had to replace the fan and the control board and now there is a problem with the electrode. It's a sealed system operating part radiator circuit and later installed underfloor heating circuit through blending valve. We need every kw of the output and I would like to replace with a condensing heat only boiler of similar output. I looked at Viessmann earlier this year and am keen to use the 100 but max output is well short of the 35kw I need. The Gloworm Ultracom HXI 38 & EcoTec Plus 438 are possibilities but after reading earlier posts everyone seems to favour the Viessmann. 'Which' have compared boilers and the HXI is highly rated but I guess my own experience of Gloworm to date says it all. Does anyone know of a good, reliable, 35kw or more output, heat only, gas, wall mounted boiler which will fit the bill (and the space) without having to completely rebuild the system.
Which heat only replacement boiler?
- Thread starter richard7186
- Start date
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I thought you were fitting Atags now? If he wants reliable, you can't say any better than Atag, surely? An E32s would be man enough for the job.
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Thanks for the very speedy replies. The spec for the HXI says it's suitable for sealed systems? Regarding output in the winter we run the Ultimate 120 almost 24/7 and have huge gas bills but I thought the greater efficiency of a condensing boiler may mean we could squeeze the same output from a smaller model? I haven't looked at the Atag or the other Vaillant but will check them out.
ATAG are certainly about the best money can by and probably one of the most reliable.
ATAG are also the most efficient boiler on the market at present.
Yes you can run the HXi on a sealed system but I still prefer to fit a system boiler, ie the 600 series Vaillant, as the HXi and the Vaillant 400 series are poor quality in comparison.
If you are looking at the mass produced boiler market, I feel that Vaillant are still top of this area.
ATAG are also the most efficient boiler on the market at present.
Yes you can run the HXi on a sealed system but I still prefer to fit a system boiler, ie the 600 series Vaillant, as the HXi and the Vaillant 400 series are poor quality in comparison.
If you are looking at the mass produced boiler market, I feel that Vaillant are still top of this area.
Are those the ones with the hose connection to the pump?
I was called to one of those leaking a few months ago and was shocked with what I saw inside a so-called quality boiler. I have fitted lots of Atags and have to say never had any of the problems seen with the mass market boilers. The Dutch know how to make reliable boilers and I am very wary to fit other makes now.
D
Deleted member 105431
I agree with gas4you but the direct replacement for your ultimate would be the glow worm ultracom 38 hxi (has just won "which?" magazine best buy). The Vaillant 637 would be my preferred choice though.
D
Deleted member 105431
Are those the ones with the hose connection to the pump?
.
the rubber hoses are sorted now and were chosen to prevent noise and vibration. Engine coolant systems endure extremes of temp and pressure far above a standard heating system and are very reliable and use a lower grade of material than Vaillant.
We would specify, in this situation, a Vaillant 637 or a Viessmann 200W 35Kw.
The Vaillants do have hoses inside (recently updated according to our resident guru, Dangermouse!) but so does the Viessmann 100 series.
The Vaillants do have hoses inside (recently updated according to our resident guru, Dangermouse!) but so does the Viessmann 100 series.
B
BigBurner
Are those the ones with the hose connection to the pump?
.
the rubber hoses are sorted now and were chosen to prevent noise and vibration. Engine coolant systems endure extremes of temp and pressure far above a standard heating system and are very reliable and use a lower grade of material than Vaillant.
But don't run for as long as a boiler and are changed around every 5 years. Another example of poor quality in boilers.
B
BigBurner
Use a Broag Avantaplus 39C combi and do not connect the DHW section. Or connect it and have it as backup using a 1/4 turn isolation valve.
http://www.avantaplus.com/index.php?content=39c
"Doctor Drivel" <[email protected]> wrote in message
news:[email protected]...
> I think the best thing for you is to drop the two boilers idea and fit one
> boiler with integral weather compensation, as I doubt you will control the
> two of them properly or efficiently.
Look at a the Broag Avantapluc 39C combi. You then don't need to connect the water section and just use the CH side. It is well priced and has integral weather compensation control. It is £917 inc VAT, that is very well priced for a 40kW boiler. A combi is a system boiler with a water section added. If you need the water part in the future you have it. Or connect it up and isolate the DHW section and use as backup only.
http://www.tradingdepot.co.uk/DEF/c.../Central Heating Boilers/Broag Remeha Boilers
Look at the combi options pages 17 to 21. The outside senors etc, are extra.
http://www.avantaplus.com/docs/Issue 5 -Avanta Schematics Booklet.pdf
As you have underfloor heating I would reconsider your control system as you are upgrading a boiler. A perfect time to re-think and make better. The Avantaplus can control UFH directly using integral weather compensation. The Avantaplus has an OpenTherm protocol control system, which Glow Worm and Vaillant do not. Look at the schematic booklet and there are a few UFH configs there.
The Vaillant 637 will do you fine, and the new Ectotec 637 comes with solid copper pipes now, as opposed to the rubber hose's.
If you went for a HXI boiler you will have issues with your Installation in relation to the size of your flow and return pipes off the boiler. I would assume that they are 22mm, so you are not going to get 38kW through 22mm pipework if you are on a S Plan or Y Plan system and your current pump location.
A 637 with built in pump will suffice but you will need to be methodical with cleansing the system before Installation and fit a Magnaclean to the system to collect the remaining Ironoxide.
If you went for a HXI boiler you will have issues with your Installation in relation to the size of your flow and return pipes off the boiler. I would assume that they are 22mm, so you are not going to get 38kW through 22mm pipework if you are on a S Plan or Y Plan system and your current pump location.
A 637 with built in pump will suffice but you will need to be methodical with cleansing the system before Installation and fit a Magnaclean to the system to collect the remaining Ironoxide.
B
BigBurner
Use a Broag Avantaplus 39C combi and do not connect the DHW section. Or connect it and have it as backup using a 1/4 turn isolation valve.
http://www.avantaplus.com/index.php?content=39c
http://www.tradingdepot.co.uk/DEF/c.../Central Heating Boilers/Broag Remeha Boilers
Look at the combi options pages 17 to 21. The outside senors etc, are extra.
http://www.avantaplus.com/docs/Issue 5 -Avanta Schematics Booklet.pdf
As you have underfloor heating I would reconsider your control system as you are upgrading a boiler. A perfect time to re-think and make better. The Avantaplus can control UFH directly using integral weather compensation. The Avantaplus has an OpenTherm protocol control system, which Glow Worm and Vaillant do not. Look at the schematic booklet and there are a few UFH configs there.
B
BigBurner
Yep. With a 20C Temperature Difference between Flow and Return.
Approx:
15mm 9 kW
22mm 24 kW
28mm 70 kW
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