Replacing a normal radiator with a tall narrow one or underfloor heating instead?

[Backto505]

This is likley to be the first of 25,000 questions

I am undertaking a diy kitchen refit on a budget of about 23.67

One of my (many) problems is the radiator is in exactly the wrong place by only about 5cm

If i were to buy a tall thin radiator it would fit in the gap, but is it difficult / expensive to extend the pipes each side? i know you can get extending valves but a) these are reputedly leaky b) i don't think they'd be long enough anyway c) they'd look rubbish

alternatively i am toying with electric underfloor heating, specifically Devimat. this looks easy enough to fit myself ( i have an electrcian friend). i've calculated this would cost about 200 for all the bits so quite possibly less than the radiator + pipework

I'm retiling the floor, and am worried about it being cold underfoot, so this may be a better solution, i know it doesn't heat as such but being small and a kitchen i don't think it needs more than the chill taking off

the room is small, 2.5 x 3 m

[PigletJohn]

£23.67 will not cover the cost of buying or installing a radiator that will be less effective at heating the room.

The running cost of electrical heating is about three times the cost of gas heating.

What are the things that would encroach on your existing radiator, and what are (all three of) its dimensions?

[Backto505]

no, i know :( but i've got nice children and kidneys to sell :)

the knob of the radiator is 50cm from the adjacent wall where i need to but a 60cm depth unit.

do you mean the dimensions of the radiator or the encroching kitchen unit?

i've made a technical drawing

[PigletJohn]

is that a kitchen unit?

What would happen if you spaced it away from the end wall by the thickness of the radiator?

Width
Height
Depth
of the radiator

[Backto505]

i've done a better one

[Backto505]

it is a kitchen unit.

the current unit has a bit cut out to go around the control knob. it looks crap and you can't adjust it easily

i'm not at home to measure precicely but at a guess it's about 60 cm wide, slightly less tall and sticks out from the wall about 15cm

do i have to start using mm now i'm pretty much a builder?

[PigletJohn]

what would happen if you fitted a 500mm unit instead of a 600mm one?

[PigletJohn]

p.s.

the knob can go on the other end

[PigletJohn]

is it a chipboard floor, or planks?

[burnishedsilver]

Electric underfloor heating is ridiculously expensive to run. You're better off getting the radiator sorted.

[Backto505]

i don't have a 500mm unit, i've rather rashley bought a second hand beautiful, handmade kitchen, handmade to fit someone elses room

the floor is concrete

[Backto505]

Devi mat claims to be economical:

Advanced controls ensure minimum
running costs of approx 0.7-1p per hour
per m2, depending on mat type and
tariff.

Tiles are awfully cold underfoot the dog will hate it

[PigletJohn]

you have a concrete floor. Do the radiator pipes come up out of the floor, or down from the ceiling, or along the wall?

Devi mat are trying to mislead you. Let's suppose a room 2500x3000mm needs 1.5kW of heat.

Electricity costs about 14p per kW hour
Gas costs about 5p per kW hour.

Their figure of 1p per hour would give you a 14th of a kW of heat. That's 71 watts. Less heat than you'd get from a 100W light bulb. You'd need about 21 m2 of mat to heat the room. How many m2 is the room?
(I already know)

[ThreeQuartersEmpty]

Electric underfloor heating is eye wateringly expensive. As said ^

Are you digging up your concrete floor to lay the mat and then screed and new tiles on top?

Or are you planning on putting the mat on top of your existing floor, then screed and new tiles. Cos your floor levels will be off if you do this.

[Backto505]

The pipes come down through the ceiling, then all over the bloody place. as an aside can these be embedded in the walls or is that not advisable?

ok, perhaps UFH is not the solution.

wonky floor levels wouldn't be an issues, we have umteen of those already

the system i was looking at is laid on the existing floor, tile adhesive applied and tiles put onto

i did understand that it warms the floor rather than heating, they're open about that, but being a kitchen i thought it may be sufficient

on the FAQ it mentions that each sqm only uses as much electricity as a lightbulb her as one of their claims towards economy

[PigletJohn]

if the pipes are surface mounted, I am sure the cheapest and easiest thing would be to have the radiator pipes altered, and the radiator placed in about the middle of the wall. Take the opportunity to have a TRV fitted at the same time, unless it already has a reasonably new one. I am especially fond of the Danfoss RAS-C2

In the event that the radiator is undersized, or going rusty (feel the seam underneath) I would go for a long low one, which will heat the room more evenly than a narrow or tall one.

If your boiler is old and does not have a pressure gauge on it, you can give the system a chemical clean at the same time. This is a fairly easy DIY job if you like basic plumbing.

BTW, on economy of electric heating,
little energy (electricity) in = little energy (heat) out
There is no way of getting extra heat out without paying for the electricity.

[Backto505]

Thanks PJ, you're a star
Our boiler is ANCIENT. We've done a chemical clean, and taken off the worst radiators and hosed the sludge out of them.

Radiator is it then. So where's cheapest? Will a cheap one = crap. Though our whole heating system will need to be replaced as soon as I find a buyer for DS so perhaps a cheap one will do for a temporary(ish) stopgap

[PigletJohn]

there are probably differences in quality, but just get a British Standard one and I expect it will do. Try here, then see what prices you find at reputable local suppliers.

Have a look round If you are fitting a TRV, and balancing the radiators, it does no harm to get one a bit bigger than you think you need, it will heat the room faster from cold.

Even though you have cleaned it before, with an open vented system, it does nothing but good to run X400 round it for a couple of weeks before you drain down, and add X100 on final fill. Plus X200 on final fill if you are in a hard water area and your boiler sings like a kettle or bangs while it is heating.

You can add a system filter if you like.