Megaflow - only tepid hot water

[marschp]

I have a megaflo system in an indirect configuration. It is about 8 years old and has never really produced piping hot water, however, in recent weeks the temperature of the water has become tepid at best. The system has not been serviced since commissioning 8 years ago and we do live in a hard(ish) water area. The immersion heater is constantly on. In the storage cupboard with the cylinder there is a 2-port valve, and a pump which seems to be connected to a programme timer.

I checked the setting of the thermostat and it was set to 45 degrees - the instructions suggest this should be set to 60-65 degrees which I have done, but it has not had any effect.

The boilers appear to be on, are warm, and the programme is set to All Day and is on.

Anyone got any idea what might be wrong?

How can I find someone best qualified to put it right?

Thanks

 

[doitall]

Is the pump for secondary circulation, what colour is it.

The immersion should be off and used as back up.

When you say boilers is there more than one, and what make/model.

How is the system configured, is there a 3port valve or a second 2port for the heating.

 

[marschp]

Is the pump for secondary circulation, what colour is it.

The immersion should be off and used as back up.

When you say boilers is there more than one, and what make/model.

How is the system configured, is there a 3port valve or a second 2port for the heating.

Hi and thanks for replying:

I don't know if the pump is for secondary circulation. The pump is yellow (its says 'Qrundfos' and 'Selectric Bronze' on it) and is connected to the cylinder inlet via a T-juntion. The other leg of the T-junction comes from the Cold Water Combination Valve.

The pump is connected to a program controller which is set to 'Twice', and is programmed as follows:
on @ 6:30am,
off @ 9:30am,
on @ 4:30pm,
off @ 9:30pm

In the storage cupboard the Cylinder Primary Flow is connected to a 2-port valve. It is quite warm, but not so hot that I can't keep my hand on it comfortably. The pipe into the other side of the 2 port valve comes up through the floor of the storage cupboard.

Downstairs there are two boilers side by side - they are Ideal Classics.

The program controller next to the boilers is a Horstmann Channelplus XL and is currently set to be on all day.


Thanks

 

[doitall]

That a secondary pump, and more than likely where the hot water is going.

Try turn it on just when you want hot water, and see what difference it makes.

If the pipe leading to the MV is only hand hot, then you need to up the boiler temperature, or find out where the heats going.

What size is the property and it's use.

Some serious lagging on the hot water circuit would be another good plan.