What are the two pipes on a radiator?

The two-pipe system consists of – you've guessed correctly – two separate pipes: one that feeds hot water to the radiators and one that conveys used water back to the boiler. In other words, the radiators are installed in parallel.

Why do radiators have 2 pipes?

With a two pipe central heating system, two separate pipes go to each radiator, one feeding the radiator (flow), and one taking the water away from the radiator back to the boiler (return). Two pipe central heating system: flow and return pipes.

What are the 2 valves on a radiator for?

Each radiator will have two valves. One will control the amount of hot water that enters the radiator and the other will balance the system by controlling how much heat comes out of your radiator.

Which is the return pipe on radiator?

A second pipe (called the 'return pipe') collects the cooled water from the radiators and carries it back to the boiler for re-heating.

Which side of radiator is flow and return?

The flow of a radiator is typically on the left as you look at it stood up or attached to the wall.

Learn How To Pipe A Radiator

Does it matter which pipe goes where on a radiator?

Most modern thermostatic radiator valves are bi-directional – so can be fitted on either the flow or return pipe of your radiator. However, it's always best practice to fit the TRV on the flow pipe that enters your radiator.

How do you know which pipe is flow and which is return?

Hi, turn the heating on and the pipe that gets hot first is the flow. Switch on your heating from cold. The pipes on the heating circuit that heats up first will the flow pipe, the other wil be the return. The Flow pipe gets warm before the return pipe.

How can you tell an inlet and outlet on a radiator pipe?

Check the valve itself and there should be a little arrow near the outlet. If the arrow points away from the valve it needs to go on the return side of the radiator, if it points into the valve it should be on the flow side.

Do radiators have an inlet and outlet?

Every radiator in a hot water system has an inlet and outlet. The inlet is to take hot water in and the outlet is to let the water back out.

Should both valves be open on a radiator?

You should open both of the valves on all of your system's radiator when you are starting the radiator balancing process. You will most likely need to use pliers to open the lockshield valve.

Should lockshield valve be open or closed?

As you progress further away from the boiler, the Lockshield valve will need to open slightly more. It's not uncommon for the Lockshield Valve in the first radiator to be open around one-quarter of a turn, while on the last radiator, it may need to be fully open.

Do I need lockshield valve?

A lockshield valve helps to balance out that radiator and ensure the whole system is in sync, with all radiators heating at the same rate. It is therefore every bit as important a valve as without the system being balanced, there is often little point adjusting an individual temperature valve.

What is the primary flow and return pipes?

The coil, or "heat exchanger" forms part of the central heating circuit, and its water heating abilities are purely a by-product of its main function, which is to heat the radiators. This heating is called the "primary" circuit, the pipes running to and from the boiler are called the primary flow and return.

How does a 2 pipe system work?

A 2-pipe HVAC system is one that uses the same piping alternately for hot water heating and chilled water cooling, as opposed to a 4-pipe system that uses separate lines for hot and chilled water. Two-pipe originated 50 or 60 years ago as a cost-effective way to add air conditioning.

What does lockshield valve do?

The Lockshield valve restricts hot water flow to radiators to help balance the entire system as a whole. Other radiator valves can be used to help adjust the temperature of a radiator to help heat or cool a room.

Should radiator valve be on inlet or outlet?

Many modern homes will have TRVs – Thermostatic Radiator Valves – attached to most of the radiators on the opposite side from the lockshield valves. A TRV should always be fitted to the inlet on the radiator and the LSV to the outlet.

Which is the flow pipe on a radiator?

tails. The one that heats fastest/first is the flow.

Which side of the radiator is the lockshield valve?

The lockshield valve, on the side of the radiator opposite the on/off valve, may be adjusted to balance the output of your heating system. The lockshield itself is the plastic cap that covers the valve to ensure that you don't accidentally change the setting once you've adjusted it.

Do radiators have a flow direction?

The new radiator is marked for the direction of flow; through the valve and in at the top of the radiator.

Why is the return pipe on my radiator cold?

This is because all pipe work and radiators are cold when you fire up a boiler. The pipes and rads absorb some of the heat, so the return water coming back is cooler. As your central heating slowly warms up, the differential in temperature between the two pipes will become closer.

Which side of the radiator does the bleed valve go?

Most radiators are bled using a radiator key but if you're not sure, find a bleed valve. They're located on the left or right side of the radiator at the top. A bleed valve on an older radiator looks like a hole with a square bit in the middle.

Is there a top and bottom to a radiator?

TBOE stands for Top and Bottom Opposite Ends, and this as the name suggest means the valves attach at the top and bottom of the radiator at opposite ends. Whereas, TBSE means Top and Bottom Same ends, meaning that both pipes enter on one side of the radiator.

Do all radiators have a lockshield valve?

Lockshield Valves Explained

A lockshield valve is slightly different from manual and thermostatic valves as it controls how much water can exit a radiator. Every radiator has one, and you need them to make sure all the radiators remain balanced in your central heating system.

What happens if a lockshield valve is closed?

On most radiators, this is the valve you can't turn by hand. By closing a fully-open lockshield valve by a few turns (with a pair of grips or screwdriver), you can slow down the rate at which water enters the radiator and reduce the speed with which it gets hot.