How does water get into expansion tank?
As hot water enters the heating system, the pressure in the system increases. As pressure increases, the diaphragm in the expansion tank is pushed down. This compresses the air in the tank, creating more space for excess water to enter.
Why is my hot water venting into my expansion tank?
a very common cause is that there is black sediment (iron oxide) causing a partial blockage. This most often occurs at the tee where the 15mm feed and expansion tank in the loft joins onto the larger circulating pipe, probably near the pump in the airing cupboard or by the boiler.
Why is hot water back flowing into cold water tank?
This happens over a period of a 90 mins (water is only heated for 20 mins). Having looked in the tank I can see that water is being backfilling the large cold water tank not via the open vent pipe but the pipe at the bottom of the tank where the cold water should flow to the Cylinder.
What causes a central heating tank to overflow?
Over time, this coil can become perforated, meaning there’s hole in the coil which allows water for the central heating into the domestic hot water being stored in the cylinder. This rise in water levels can then lead to the feed and expansion tank overflowing.
Where is the expansion pipe in a central heating tank?
The cold water top up tanks are above that, then the expansion return pipe is about 1 foot above that, returning back in to the central heating top up tank. I have noticed the central heating top up tank is very rusty now, and the water is not black anymore, it is red i.e. rust. When I usually drain the system it is usually black.
Why does a hot water heater have an expansion tank?
As water is heated, it expands and its pressure in the tank vessel will increase if there’s no room for thermal expansion. The old domestic hot water heater plumbing systems were designed so that the expanding water in heaters would push some water back outside the house – into the public water main, which would absorb the pressure.
Why does hot water run out of expansion pipe?
It still pours water out of the expansion pipe on either hot water or central heating setting. I have also noticed that the system is really noisey. The downstairs radiators are fitted with automatic valves which are all open.
Why does my hot water heater need to run all the time?
To make up for the loss of hot water, your tank would need to run more frequently to keep the same level of hot water as before. If your water heater is constantly running the first thing you should do is check the unit and the pipes immediately around it for leaks.
The cold water top up tanks are above that, then the expansion return pipe is about 1 foot above that, returning back in to the central heating top up tank. I have noticed the central heating top up tank is very rusty now, and the water is not black anymore, it is red i.e. rust. When I usually drain the system it is usually black.
