Intergas have applied for a patent, but it will a long time before it is granted, if at all. As at 1/3/2010 the status was "a search report has been drawn up", i.e a trawl through existing patents to see if the idea had been patented before or the idea is nothing new aka "prior art".
Combi boiler - how big/which one?
- Thread starter Ambra
- Start date
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I've just had a look at the Intergas compact HRE 36/30.
It seems staight forward enough and not that bad,
however;
The flow rate is quoted as 13 l/min at a 35 degree rise, the vaillant 837 figures are 12.6 l/min @ 42 degrees and 15.2 l/min @ 35 degrees.
Good boiler for some applications assuming the cost is competitive, but not what the OP was really after.
Psst the GW Ultrapower 170 has an eco tec heat engine - would cost a lot more with a bunny badge!
Cheers
It seems staight forward enough and not that bad,
however;The flow rate is quoted as 13 l/min at a 35 degree rise, the vaillant 837 figures are 12.6 l/min @ 42 degrees and 15.2 l/min @ 35 degrees.
Good boiler for some applications assuming the cost is competitive, but not what the OP was really after.
Psst the GW Ultrapower 170 has an eco tec heat engine - would cost a lot more with a bunny badge!
Cheers
Oh dear
I hope our own does not develop this fault, it is going to be 2 years old next month and out of guarantee
dont worry dave. most common problem is the nrv in the pump sticking. it can be removed. We'll talk u through it if it ever comes to it. your getting good at this boiler repair lark right?
interesting, did a little digging and found Patent Application WO/2010/002255 which i believe is the one you are talking about.
since they have been making this type hx over 10 years and the patent (WO/2010/002255) shows only latest version of the HX (the maze looking type) i would suspect it is only the latest patent Application you have found.
could be wrong...but if other manufacturers could copy it they would
since they have been making this type hx over 10 years and the patent (WO/2010/002255) shows only latest version of the HX (the maze looking type) i would suspect it is only the latest patent Application you have found.
could be wrong...but if other manufacturers could copy it they would
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Whoever suggested that?
Just as well as he is not too tall, but he is knowledgeable about their boilers though!
Tony
Oh dear
I hope our own does not develop this fault, it is going to be 2 years old next month and out of guarantee
dont worry dave. most common problem is the nrv in the pump sticking. it can be removed. We'll talk u through it if it ever comes to it. your getting good at this boiler repair lark right?
If it's as easy to work on as my Grans Turbomax then I'm happy
Oh dear
I hope our own does not develop this fault, it is going to be 2 years old next month and out of guarantee
dont worry dave. most common problem is the nrv in the pump sticking. it can be removed. We'll talk u through it if it ever comes to it. your getting good at this boiler repair lark right?
If it's as easy to work on as my Grans Turbomax then I'm happy
its quite tricky, but i've done it many times and got it down to a fine art, so i should be able to ive you good instruction. Be good experience for u
its a decent design, but dont get carried away. If they wanted to copy it, trust me they would.
Oh dear
I hope our own does not develop this fault, it is going to be 2 years old next month and out of guarantee
dont worry dave. most common problem is the nrv in the pump sticking. it can be removed. We'll talk u through it if it ever comes to it. your getting good at this boiler repair lark right?
If it's as easy to work on as my Grans Turbomax then I'm happy
its quite tricky, but i've done it many times and got it down to a fine art, so i should be able to ive you good instruction. Be good experience for u
Check your messages
Ok, it is a month since I started this thread, and you advice has been helpful. We are hoping to exchange the contracts this week, and then we will be getting some quotes for the work.
I would like to go for Viessmann, but it will all depend on what engineers can do, etc.
I am trying to 'educate' my other half about all this, but he is not interested much in this, as long as it doesn't cost all the money in the bank.
So, one more question, if I may.
My idea was to replace radiators at the same time as the boiler (and removing hot water tank in the airing cupboard + tanks in the loft). The radiators are over 20 years old. Would you replace them or leave them as they are? Well, they would at least need to be repainted, as the rust is showing up on them by now.
Upstairs most of them are single, downstairs living room and kitchen have double ones (tiny one in the kitchen). I know, I have to do some calculations on what sizes are needed for the room, and I will get to that, but I do not know what BTU's are the current ones.
I would like to go for Viessmann, but it will all depend on what engineers can do, etc.
I am trying to 'educate' my other half about all this, but he is not interested much in this, as long as it doesn't cost all the money in the bank.
So, one more question, if I may.
My idea was to replace radiators at the same time as the boiler (and removing hot water tank in the airing cupboard + tanks in the loft). The radiators are over 20 years old. Would you replace them or leave them as they are? Well, they would at least need to be repainted, as the rust is showing up on them by now.
Upstairs most of them are single, downstairs living room and kitchen have double ones (tiny one in the kitchen). I know, I have to do some calculations on what sizes are needed for the room, and I will get to that, but I do not know what BTU's are the current ones.
Ask Viessmann for names of installers who can give a five year warranty.
If you replace them, you can at least make sure they are correctly sized.
The correct way is to use a heat loss program such as Stelrad Stars. But you could get a reasonably accurate idea by allocating the total boiler output to each room as shown below You have to deduct 2kW from the calculated boiler size, as this is the allowance for the hot water cylinder.
For example:
Boiler output = 18kW - 2kw = 16kW for heating
Total floor area = 80m²
Requirement = 0.2kW per m²
Room area = 12m²
Heat required = 12 x 0.2 = 2.4kW radiator
You can find the output of your existing rads from a manufacturer's catalogue. There is very little difference between manufacturers for the same size and type of product so the Stelrad Elite Catalogue is as good as any. For unusual rads use the Guide to Radiator Outputs
If you want to have the boiler condensing as much as possible the return temperature needs to be below 55°C. Now rad outputs are measured under defined conditions: Flow temp = 75C, Return temp = 65C, Room temp = 20C. If you alter any one, the output will change. You have to allow for this when sizing your rads. So for flow = 75C, Return = 55C, Room =21C , you will have to oversize the radiator by 20%. This is because the rad will be giving out less heat than the mfrs literature says. So, if the size of the rad works out at 2.4kW, you install a 2.88 rad (say 3kW). You do not increase the boiler size by 20%!
You said earlier that the house was built in 1988. In that case it is unlikely to have any cavity insulation. Check out the Grants site I mentioned in a previous post.
Thanks for the explanation! The house has cavity wall insulation according to the previous owner (landlord) and the original house specification. We will be increasing loft insulation, as it is not much there now. I was going to get the tanks removed first, and then sort out the loft insulation, as we will want to have at least some area boarded for storage.
If the house was built in 1988 do the pipework to the ground floor radiators run under the solid floor?
That's a little worry for me though I do worry sometimes unnecessarily, most of the time actually.
If it is buried can you see a bit of felt or insulation where the pipe comes out of the screed into the radiator valve?
Charging a combi system from the main can achieve a pressure 5 times that of an open feed system and old pipework just covered in screed has had nowhere to move. After several years of flexing at the joints the increase in pressure can create a leak that wasn't there before.
Just a concern of mine.
Unless the radiators are the old Servowarm pattern, which they will not be if only 1988, they'll probably take the pressure OK but flush them whatever. There's a guy at Viessmann training who says it is not necessary to flush the old system with their heat exchanger but more of their trainers say it is and I agree with them; especially if it's a combi. I think all their service engineer agree with that as they have to do the follow up. The m.i. ask for it anyway.
If it's a minibore pipework system flush the radiators individually not just through the pipework. If you can afford it fit a dirt separator (my preference is the Spirovent range 'cos I like metal things which don't break as easily as plastic).
That's a little worry for me though I do worry sometimes unnecessarily, most of the time actually.
If it is buried can you see a bit of felt or insulation where the pipe comes out of the screed into the radiator valve?
Charging a combi system from the main can achieve a pressure 5 times that of an open feed system and old pipework just covered in screed has had nowhere to move. After several years of flexing at the joints the increase in pressure can create a leak that wasn't there before.
Just a concern of mine.
Unless the radiators are the old Servowarm pattern, which they will not be if only 1988, they'll probably take the pressure OK but flush them whatever. There's a guy at Viessmann training who says it is not necessary to flush the old system with their heat exchanger but more of their trainers say it is and I agree with them; especially if it's a combi. I think all their service engineer agree with that as they have to do the follow up. The m.i. ask for it anyway.
If it's a minibore pipework system flush the radiators individually not just through the pipework. If you can afford it fit a dirt separator (my preference is the Spirovent range 'cos I like metal things which don't break as easily as plastic).
Hi,
I am not sure if the pipework runs under concrete floor. On the ground floor, the pipes for the radiator come out above the skirting board, and it is a pipe, not a flexible plastic hose type thing we had in a previous house.
I would definitely want a flush of the system as after the replacement ensuite and fitting of the shower pump, the pressure in hot water taps dropped dramatically and I guess it is debris in the system that caused this to some extent (well, the hot water tap in the kitchen had brown water running through and just a trickle of water coming out, so landlord had to remove it and clean it, and it was confirmed that it was debris blocking it).
Can anyone estimate how much the replacement radiators are likely to add to the price of boiler replacement? (I just want a ballpark figure, so I can prepare my OH for when the quote comes through). There are 11 radiators to be replaced in total (varying sizes, the largest one would be about 1.6m by 0.5m in living room, the smallest one in the kitchen)
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