Worcester Greenstar / Megaflow tank but - no hot water

[youngloch]

Just moved into our house and when we moved in all the heating had been turned off. In the loft there is a Greenstar Condensing Boiler a small red tank and a Megaflow tank.

We have a programmable control box with a room thermostat to control the central heating and under the box are two switches, one which is for the boiler and one, I believe, for the Megaflow tank.

The problem is that even though we have set the hot water and central heating switches to on (and have been for several days) that unless the Megaflow tank is on as well we are not getting hot water.

Am I right in thinking that the boiler should be producing hot water to the tank without the Megaflow tank being switched on as well?

The concern is that if we have the Megaflow tank switched on all the time that we are just burning electricity?

 

[Murf520970]

is the tank stat turned up ?

 

[youngloch]

It has two dials for temperature, one for heating and one for water, it has a sticker saying the water gauge is not operational but the other one is turned up.

 

[picasso]

What is the make/model or number of programmer ?

 

[youngloch]

It's a Siemens RWB29

In case it's relevant the only thing I have done (other than switch it all back on when we moved in) was to alter the central heating temperature on the boiler from 5 to 4

 

[picasso]

Are both red lights on the programmer lite and do you have central heating ie does the boiler actually fire up ?

 

[youngloch]

Yes the lights are on, in fact for hot water I've set it to manual and always on at the moment (but made no difference) and yes the central heating works. I've been in the loft and had my wife running the hot tap but it just doesn't fire up. Put the central heating on and it fires instantly.

 

[McCombi]

Are you saying there are 2 isolation switches under your control box? One isolating Greenstar and one you believe to be the electric immersion heater of the megaflow. Could it be that its not immersion switch but maybe an isolation switch for a 2 port valve for Megaflow.
Its a possibility. Can you provide a photo of switches and cables from it if any?

 

[youngloch]

Programme and switches in airing cupboard

• youngloch
• 6 Aug 2012
• 1

System in the loft

• youngloch
• 6 Aug 2012
• 1

Wireless box

• youngloch
• 6 Aug 2012
• 1

Red led (next to alarm) occasionally flashes

Megaflo tank

• youngloch
• 6 Aug 2012
• 1

First pic is in the airing cupboard and the other three are the actual system in the loft

 

[picasso]

View media item 48928
Turn the hot water on on the programmer and see if the lever has gone "sloppy" if it has then chances are the 2 port valve is knackered, I have marked the valve you need to check.

 

[youngloch]

I checked the lever and it is set to auto - when I slide it across it has a proper electric winding noise as it slides back to auto

 

[picasso]

If you want to go any further you will need a multimeter and be confident working with mains voltage.