Installation of hot water cylinder

Filikin

I got quoted €500 to install a fit a 150litre water cylinder (emersion tank - the thing that heats the water for a bath).
thought that was fine, until I realised that the bath holds 280litres.
So I asked for a 250litre tank and the price went up to €800
In addition the plumber says that because the water tank in the attic only holds 200litres, there are further complications.

Am I been done?

JohnnieK

You have to take into account the cold water that would be in the bath aswel. A standard domestic cold tank holds around 200L anyway. A standard domestic cylinder would hold 96L. The capacity of your bath would be from top to bottom. The actual capacity would be less. That quote sounds right to me. When you jump in size with cylinders the price dose rise a good bit and copper is through the roof at the moment. If your mains pressure is o.k I would say you would be safe with the 150L tank. If its very poor then I would up the size of the tank in the attic so it will cope.

Micky Dolenz

A standard cold water storage tank has a nominal volume of 60 G but has an actual volume of about 50G. That's about 230L, Depending on your cylinder, if it's 18" wide by 30" high, it will have a volume of 125L.

As JohnnieK says,The bath volume won't be as much when you are lying in it and you will use cold water too.

If water in the cylinder is 60C, you will use far more cold water than hot to fill bath.

The only problem you may have is if you have a high pressure pump, it could empty cold water storage tank very quickly if filling bath.

Filikin

Micky Dolenz wrote: »

A standard cold water storage tank has a nominal volume of 60 G but has an actual volume of about 50G. That's about 230L, Depending on your cylinder, if it's 18" wide by 30" high, it will have a volume of 125L.

As JohnnieK says,The bath volume won't be as much when you are lying in it and you will use cold water too.

If water in the cylinder is 60C, you will use far more cold water than hot to fill bath.

The only problem you may have is if you have a high pressure pump, it could empty cold water storage tank very quickly if filling bath.

Our pressure is good enough that I don't need a pump to deliver the hot water to the bath, so what I am hearing is to let him go ahead with the 150l tank? many thanks.

yoshytoshy

The only reason you would need a larger cylinder is ,if you previously hadn't enough hot water.
If he's replacing like for like ,then you're not going to have any new problems.

Filikin

yoshytoshy wrote: »

The only reason you would need a larger cylinder is ,if you previously hadn't enough hot water.
If he's replacing like for like ,then you're not going to have any new problems.

I'm also replacing the bath with a much bigger one. This one holds 280l when full.
If the hot water is at 60DegC and the target is 40DegC, and allowing 80l for the body in the bath, I am guessing that 150l is just about enough.
so maybe I should aim for a 200l cylinder.
But I don't want to be heating water that is never used.

yoshytoshy

If you're getting a bigger bath ,you should really get a bigger cylinder so.

Even if you went up a size it would help ,from 30x18 to 36x18.
It shouldn't cost that much extra either.

Filikin

since the bath will be 280litres, I think I am looking at either 48" x 18" (166l) or 54" x 18" (196l)
Trying to figure out how big a tank I actually need is the problem - I don't want to get a new tank and discover it is not big enough for the new bath.
Neither do I want to get a new tank and find I am only using half the water in it.