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  • Hot Water Problems Again

    Hot water problems

    If you are experiencing hot water problems with your boiler there are many reason why that might be.

    Let look at the combination boiler first.

    Most of today’s combination boilers have a hot water plate exchanger.

    Cold water passes through the plate and is heated up and then leaves the boiler for the taps. 

    This plate is heated by the heating water. 

    These two waters never mix. 

    Hot Water Problems

    The plate works on the same principle as a pot of how water.

    If you put a bottle of cold water into the pot, after a short while the bottle of cold water will reach the same temperature as the pot. 

    With the plate the two waters are so close together that the cold water is heated instantly.

    Now if you are having hot water problems.

    Like the water going hot then warm but never staying hot enough to wash or shower.

    Then plate is partly blocked with sludge. 

    This is the most common problem with combination boilers. 

    Thermistor that senses the temperature of the water very rarely becomes faulty.

    Heat plate exchange cannot be cleaned out as the water ways are very small.

    Once they become blocked, it will need to replaced with a new one. 

    They are quite expensive to buy. 

    What you have to consider is if the plate is blocked.

    Then the main heat exchanger may also be party blocked as it’s the same water that passes through them. 

    Hot Water Problems

    If you go down the road to replace the plate exchanger.

    Then it’s a good idea to have your boiler and system flushed out with cleaning chemicals to remove all the debris and sludge. 

    At the same time as the flush, it’s advisable to fit an inline filter to the boiler. 

    They are fitted on to the return pipe, as close to the boiler as possible.

    The filter will stop any sludge entering the boiler and causing problems. 

    Once the system is flushed out an inhibitor should be added to stop the sludge build up. 

    The inhibitor should be checked each year, and topped up if necessary. 

    If you just replace the plate without the clean,then the same problem will re occur.

    Now we go on to boilers that are connected to a hot water cylinder. 

    If you are experiencing hot water problems we need to check a few things

    First we make sure that the programmer is switched on for hot water and sending a signal to the thermostat.

    This is normally fitted on the lower part of the cylinder. 

    The thermostat if working correctly then sends a signal to the zone valve to open.

    If the valve opens, we need to check that it is sending a signal to the boiler to light up.

    The most common problems with this type of system is the zone valve motor becomes faulty.

    And the valve sticks either in the open or closed position. 

    If it gets stuck in the close position then the hot water will not work. 

    Now if it gets stuck in the open position the boiler will stay on and you will have no control over it. 

    You can normally replace the motor heads on most zone valve, they are inter changeable. 

    When removing the motor you will see the pin that the motor turns.

    You need to see if you can turn it by hand.

    It moves freely then a new motor will cure the hot water problems. 

    If the pin is stuck or hard to turn then you will need to replace the whole valve, as its probably smudged up inside. 

    If this is the case then as with the combination boiler it’s advisable to have the system flushed out.

    The hot water programmer and the thermostat very rarely become faulty.

    It’s always normally down to the zone valves on this type of system. 

    It’s very important for the water in your boiler to be clean and protected with inhibitor. 

    Otherwise overtime you find you will have hot water problem along with heating problems.

    And as most of you know the problems always happen when you need hot water or heating most.