Surely not just an immersion heater?

totsa123

We have just moved into a new build house - all great so far but we cannot work out the hot water system.

In the garage we have a boiler (not combi) and a 300l hot water tank. We have a control panel for the heating and hot water where you can programme times for each. The instruction leaflet confirms this is two separate zones ie you can programme hot water and heating separately.

if you turn on the heating the boiler fires up and the radiator symbol starts to flash. If you turn on the hot water, seemingly nothing happens. There is a hot water symbol on the boiler constantly, but the boiler does not turn on or this symbol flash when you turn on the hot water on the control panel - we have tried all the programmes such as constantly on, timer and boost and the boiler does not fire up for any of these on the hot water side. 


we asked the builders who turned on the immersion heater switch and said this needed to be on. However we can’t possibly imagine the tank can only be heated by the immersion heater? 

I can’t post pictures as I am too new to the forum apparently - but the tank has 4 pipes going in, one clearly labelled immersion heater and another with a thermostat turned to 65 degrees. 

The wiring from the control panel seems to lead to the boiler, and the presence of the hot water symbol on the boiler suggests to us that the hot water tank can be heated by the boiler rather than solely by the immersion heater? 

I’ll post pictures as soon as possible and appreciate it might be challenging to offer any insight without these but if anyone has any ideas please do say - slightly worried we may have bought a house where water can only be heated by immersion heater??? 

totsa123

Photos now uploaded 

Netexporter

The boiler won't fire up if the water is already up to temperature and it will always be up to temperature if the immersion heater is on. So turn off the immersion, run a bath, and see if the boiler fires up then.

totsa123

Netexporter said:

The boiler won't fire up if the water is already up to temperature and it will always be up to temperature if the immersion heater is on. So turn off the immersion, run a bath, and see if the boiler fires up then.

Thank you - agreed, we turned off immersion heater switch as soon as we had some hot water yesterday. We do still have some hot water coming out of taps so not sure if this is because we haven’t used all that the immersion heater heated yesterday but boiler isn’t firing still and immersion heater was turned off about 24 hours ago

Reed_Richards

totsa123 said:

I can’t post pictures as I am too new to the forum apparently - but the tank has 4 pipes going in, one clearly labelled immersion heater and another with a thermostat turned to 65 degrees. 

A cylinder that is just heated by an immersion heater would have an inlet pipe for the cold water and an outlet pipe for the hot.  The fact that you have four pipes is a strong indication that your cylinder can be heated by the boiler, if you can figure out how.

Netexporter

totsa123 said:

Netexporter said:

The boiler won't fire up if the water is already up to temperature and it will always be up to temperature if the immersion heater is on. So turn off the immersion, run a bath, and see if the boiler fires up then.

Thank you - agreed, we turned off immersion heater switch as soon as we had some hot water yesterday. We do still have some hot water coming out of taps so not sure if this is because we haven’t used all that the immersion heater heated yesterday but boiler isn’t firing still and immersion heater was turned off about 24 hours ago

Have a look at the motorised valve on the higher of the two pipes at the bottom of the cylinder. There is often a manual over-ride on them. Make sure that is in the "middle" position, so it is actuated by the boiler controls. It may be set in the off position, which will prevent the boiler firing.

Netexporter

And get the builders back to insulate all that pipework.

totsa123

Have a look at the motorised valve on the higher of the two pipes at the bottom of the cylinder. There is often a manual over-ride on them. Make sure that is in the "middle" position, so it is actuated by the boiler controls. It may be set in the off position, which will prevent the boiler firing.

Thank you - apologies for ignorance, is that this one?

Netexporter

Yes, that little lever sticking out should be free to move. You'll hear the motor turn when you move the lever.

totsa123

I’ve just checked - it’s set to auto with the other end being ‘man open’

Netexporter

Where is the hot water temperature control, on the boiler, set? Try turning it fully to the right. That may prompt the boiler to fire.