Vaillant vs Main - new CH system, old house - confused!

[minniejp]

Just bought an old (Victorian terrace) fixer-upper that needs plenty TLC. No electrics, no central heating... Work starts in ten days. Has 5 bedrooms and will eventually have 1 main bathroom and 2 shower rooms.

Can't afford to have radiators put in yet (12 medium - large plus underfloor heating in kitchen), but the boiler and some main arteries will be fitted. Had a Vaillant in my old house and it worked brilliantly, no problems at all for the five years we had it. Was going to go with them again (ecoTec plus 637 and a uniSTOR 260 ??)... Plumber recommended a sealed system boiler with a hot water cylinder, but strongly suggested Main. I know they're cheaper, but I'd rather pay the extra (? £1k) for a good reliable system that will provide what I need if it's worth it.

Anybody any strong opinions either way? I have a baby girl and a part-time job, so reliability is key (though I know this will never be 100% with any boiler, there may always be a random problem!).

Second (stupid?) question - is there a reason not to put the hot-water cylinder in an insulated cupboard in the (boarded-out, well-lit, easily-accessible) loft? Building regs? The (new) ceiling below it would be strengthened.

Many thanks for any advice you could give me.

Jennie

 

[simond]

Vaillant make a nice boiler and the cylinders are well made too.

Main are the cost reduced side of Baxi Potterton, who recently, after financial issues, became part of the Dutch group who own Remeha. Main models are similar to the Baxi Pott stuff, with the exception of one aluminium unit which is unique.

I guess it comes down to what you think is important. We could probably all make do with a Hyundai car of one model or another, and it will be cheaper than most. But not everyone buys one.

Vaillant are one of the four gas manufacturers we like, so if I was quoting for your job I'd probably specify either a Worcester or a Vaillant.

Plumbers have a habit of oversizing boilers, see the boiler sizing calc on www.sedbuk.com to see what your house needs, if you live in a rectangular house it is easy.

There aren't any major technical problems with siting your unvented cylinder in the loft, except that if you are limited in terms of incoming water pressure, you will give away some performance if the cylinder is higher than the shower outlet.

 

[minniejp]

Thanks!!

I'm not the biggest Hyundai fan - if you reckon a Main is the boiler equivalent, then I'm thinking I'll be a bit more confident in requesting a Vaillant from my plumber..!

The cylinder could be located right above the main bathroom (shower) - that might help. Good to know we could use that otherwise wasted space!

Jennie

 

[adlplumbing]

nothing wrong with main boilers
been to more vaillant breakdown then main

 

[minniejp]

Is that because Main are really good, or because less of them are fitted do you think?

Thanks

Jennie

 

[simond]

Aha! Very good question.

Vaillant sell around 300,000 units pa I believe. Main are nowhere near. In fact, I could count the number of Mains I've seen on one hand.

 

[ianniann]

Hyundais are very reliable, in fact more reliable than any other non-Japanese brand. Clearly people buy cars on some other criterion, and presumably boilers too

 

[minniejp]

True true, perhaps I'm a boiler snob?!!! Am I suckered by all the whizzy gadgets I wonder?! That's what I was hoping to check with you all!

 

[vulcancontinental]

Second (stupid?) question - is there a reason not to put the hot-water cylinder in an insulated cupboard in the (boarded-out, well-lit, easily-accessible) loft? Building regs? The (new) ceiling below it would be strengthened.

Opinion: You use the sink tap or appliances 20 times a day - you use the bathrooms a couple. If you have a three storey house or the loft position for the cylinder is a long way from the kitchen you can look forward to ;-

1: a long wait for hot water to get there after you open the tap.
2: wasting a lot of clean water unnecessarily.
3: when you get your hot water at the sink and turn the tap off you can contemplate all that hot water that now sits in the pipe between the sink and cylinder growing cold after you just paid to have it heated and now you can heat some more.

I seem to recall the recommended maximum distance between source and use of hot water was 19' or 6m?

I wrote the following to submit it to the FAQ section and it applies to combi's in a roofspace (a pet hate of mine) but the principle is the same

Knowing the limitations on my own math it’d be advisable to check this yourself but if 1m of 15mm contains .176 litres and the distance from combi to sink is 20m every time the sink tap is run 3.5 litres of cold water is wasted and the customer has to wait the time it takes to run it off before the hot gets to the tap.

What’s worse of all however is that when the hot water finally arrives and has been used the tap is then of course turned off and 3.5 litres of perfectly good hot water sits in the pipe and grows cold. Plus the water in the boiler and heat exchanger, say six litres.

If the client runs the kitchen sink tap 20 times a day 120litres are heated and not used as hot water.

At 2008 prices this equates to around £40 a year – a customer’s money spent for nothing except waste of their fuel, water and time.

If the hot supply pipework is 22mm then the amount of hot water wasted is greater.

 

[minniejp]

That is very valid!! Not just wasting heated water, but wasting perfectly good cleaned water...criminal western extravagance.

So, everything is to be sited in the 2 storey rear (original) extension of the terrace - the boiler in the ground floor kitchen 1 metre sideways from the kitchen sink. The main bathroom is directly above, and i was going to put the cylinder literally directly above the boiler (2.7m up). Putting it in the loft above (adding 2.5 m to the height, nothing laterally) would free up more space for a shower in the bathroom.

Do you think that there would be excessive wasted water? I suspect the main useage of the hot water would be in the bathroom, which would be directly below. The washing machine and dishwasher both operate on cold feeds purely.

Thanks for your valuable input,

Jennie

 

[East Kent Coastal]

1: a long wait for hot water to get there after you open the tap.
2: wasting a lot of clean water unnecessarily.
3: when you get your hot water at the sink and turn the tap off you can contemplate all that hot water that now sits in the pipe between the sink and cylinder growing cold after you just paid to have it heated and now you can heat some more.

Unless you put in a secondary return, which most unvented cylinders have provision for, and lag well...

 

[ianniann]

Lagging pipework within the body of the house isn't such an issue, since most of the year you are just adding a little extra useful heat. Hot water supply pipes, and to some extent the boiler itself, within an unheated area really are just wasting heat. It can be significant, and even if you lag the pipes, hot water sitting in them is still going to eventually dump the heat into your loft or garage. The 40 quid a year figure is certainly representative of money spent heating water that you never get to use as hot water, but hopefully a good chunk of that ends up keeping your house warm indirectly.

Wasted water is inevitable. These days, with powerful combis and preheat functions, most of it is from the length of the pipework between the boiler and tap or shower. Running 4-6 litres of water every time you want hot water is a good rule of thumb, although it could be less from a tap right near the boiler. In a shower that may well be 10 litres or more because the cold will also be running. With a bath there may be no waste at all if the initial cold run goes into the bath. I collect that water for my plants, but you either need a lot of plants or only use hot water a couple of times a week! How manic are you about saving water?

 

[minniejp]

Not totally manic if I'm honest, but it bothers me when I think about it - rubbish, huh?!! Will be on a meter in this house though, so that ought to teach me a bit. We don't have crazy long showers every day and we do pay attention to turning the tap off when brushing teeth etc...that sort of level of effort.

Why am I telling you about my teeth brushing habits?!!! I understand your points though and appreciate the advice to make sure all the hot pipes are lagged properly. Things like that wouldn't occur to me to check with the plumber - he might well have done it anyway, but doesn't hurt to be informed, right?

Thanks

Jennie

 

[East Kent Coastal]

Lagging pipework within the body of the house isn't such an issue, since most of the year you are just adding a little extra useful heat.

Yeah, I wouldn't lag CH pipes under the floors of used rooms for that reason but HW is a different matter. Which is what we're talking about. Not lagging HW pipes so they can inadvertently heat your home seems ridiculous to me...

 

[minniejp]

Right, will double make sure that HW is lagged and that the cylinder is sited as close to the (main) bathroom and kitchen as possible. Excellent!

Also, just did the sedbuk boiler size calculation (came out with a required boiler output of 21kW) - the 637 is WAY over the top for my house!! Which makes it less efficient anyway - bigger is not better in this instance, right? With the radiators and bathrooms we will have I think now that a 624 or 630 (??) is plenty big enough, and coupled with a 180 or 210 cylinder.

This is really very helpful - giving me a lot of clarity...I was feeling particularly fuzzy headed. Thank you all.

Jennie