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Tips How to Balance Your Radiators

Balancing your radiators really means ensuring that all the radiators get equally hot in about the same time.

Sometimes people find that the radiators further away from the boiler are cooler than the radiators that are closer by.

If this is the case your radiators could need to be balanced.Before you try balancing them please make sure that the
radiators have been bled. We have some tips how to bleed your radiators. When air gets trapped in the radiator it will
not function properly and it will also corrode which could lead to bigger problems.

Before attempting to balance radiators, make sure the pump is not set at too low a speed. If you turn up the speed this may actually allow the radiators which are further away to heat up.

If it causes your system to pump water over into the feed and expansion tank or causes air to be pulled down the open vent pipe into the system you may have to slow the pump down again. This usually means that there ia a fault or blockage somwhere else.

Almost all radiators have 2 radiator valves which are usually at the bottom on opposite ends. Water enters the radiator through one valve which is the flow valve and leaves the radiator through the other valve which is the return valve. Adjusting radiator valves can make the valves leak.

Some manual valves have gland nuts which are already tightened hard down and are sealed internally by an 'O' ring. If the O ring gets worn or is unsettled you may need to replace this washer or even the valve.

To start balancing start by opening all radiator valves fully, both flow and return.

Then turn on the heating system from cold as it will be impossible to determine otherwise. If all the radiators become similarly hot in around the same time then you do not need to do anything else as your radiators are balanced. If this is not the case then you need to go to the radiators which get hottest the quickest and restrict the flow through them. This pushes more flow through the remaining, slower, radiators.

If it is possible restrict the flow on the valve on the return end (the cooler end).

To balance a poorly designed system it may be necessary to close a valve more than 80%.

To restrict the return valves on the hottest radiators you get a spanner and tightnen the valve by turning clockwise..

Having restricted the return valves on the hottest radiators by at least 50% to begin with, please wait to see what effects these adjustments do.

Cooler radiators will hopefully begin to to get warmer. If some are still cool you may need to repeat the process by restricting all the hotter radiators, some which we restricted before get closed even more (always on the return end) and some which weren't restricted first time round are restricted this time because they are now hot. You will only know when you heat the system up again from cold.


(Legal disclaimer: The information provided here is given in good faith and is only an indication of what we have tried to resolve heating and boiler problems. You must make your own judgements and we can accept no liability for any damage or injury sustained as a result of trying what we have attempted to do)
©Lenehans 124-125 Capel Street, Dublin 1

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