missing hot water expansion tank ??

butterfingers

Hi,

Should there always be a hot water expansion tank in the attic ?

I was in my attic over the weekend and noticed that there is just
a large main water tank, but no smaller hot water tank. Is that
normal ? There are two pipes feeding into the tank - one
is definitely the rising main (with ballcock), and I'm assuming the
other is from the hot water cylinder ?

The main water tank is plastic and looks pretty new (some of the
pipes coming out from it are light brown plastic rather than copper).
The original old metal tank was left in the attic, and there doesn't seem
to have been a hot water tank originally.

The house has gas central heating (new'ish wall mounted boiler).

I'm just curious as in all other houses I've been in there was a small
tank beside the main one in the attic. Is the standard now to just have
one tank or did the original owners try to save money by just replacing
one tank ??

Thanks a lot !

butters.

landydef

most likely you have a sealed heating system nearly all heating systems installed in the last 15-20 years here are sealed,you probably have a filler in the hot press and a expansion vessel somewhere on the system to replace the expansion pipe

butterfingers

Hi Landydef,

How big would the expansion vessel be ? All I can see in the hotpress
is the large copper cylinder and there doesn't seem to be anything
else in the attic besides the plastic water tank.

The plumbing in the house is a bit weird, which is why I was wondering
had the original owners skimped on getting the other tank fitted

thanks a lot !

butters.

Alun

Sometimes the expansion vessel is mounted above the central heating boiler, often hidden behind a casing so it's not obvious.

311

Your house more than likely had an old steel heating tank ,along with the main steel tank.
Anytime I replace a boiler ,I give the person in the house the option of a new plastic tank or just get rid of the steel one.
Everyone gets rid of it to be honest without replacing it ,theres no need for it on a sealed heating system.

There are tubes of inhibitor available that go directly into the rads ,so that leaves no need for a tank at all.

Theres also gas boilers with vessels built inside them ,so you might never see a vessel on a heating system.

butterfingers

Thanks all for the replies. I'll have a more careful look at the system
and see if I can figure it out. The reason I thought I needed a second
tank was because there is definitely a second pipe feeding into the
main tank which I'm assuming is an overflow pipe from somewhere (not
the boiler as I know where its overflow pipe is).

Thanks again.

butters.