Vaillant auro stor water heater help!

[TallulaB]

Hello,

Hoping someone can help! Not sure what else to try.

We have a Vaillant eco tec boiler and we also have a Vaillant auro stor water heater, but for the last two months all of our hot water is coming out Lukewarm. When we first moved in it worked perfectly and the water was super hot. Our heating works fine, the radiators are super hot so our thinking is that the issue is the water heater and not the boiler.

We've tried restarting it, updating the settings, turning up the temperature on the boiler. But nothing has worked. There's a pressure gauge near the heater (pictured) and the needle is all the way down, could this be the issue? The pressure on the boiler is fine, and we know how to repressurise that, but this one doesn't seem to have the same knob though so we can't work out how to repressurise.

Separately, our electricity bill seems unusually high for a one bedroom flat. So we're wondering if this could be linked? Is the water heater working too much and driving up the electricity cost?

I hope someone can help, it's driving us a little mad!

 

[CBW]

@ScottishGasMan - are you familiar with these? Would it be the pressure?

 

[ScottishGasMan]

You can't top up the pressure on a solar thermal system manually. It needs a particular Glycol Mix and special unit to fill them with that a solar thermal engineer would carry. That cylinders over 10 years old (from production date) so do you know when it was last serviced? as Solar thermal glycol loops will need flushed and replaced over time anyway due to degradation from the excess heat in them.

You need a specialist engineer that deals with Solar Thermal, and specify its a Vaillant system as its better if they know the controls for it, the boiler should be kicking in to top up the heat in the cylinder when its not reaching temperature which obviously isn't happening correctly and would need someone who knows the controls to check that.

As far as electricity use is concerned, no it should have no impact on it. The only exception being if you were heating the cylinder via the electric immersion backup heater which would cost a noticeable amount to run, but it doesn't look like that's happening or you'd have hot water.

 

[CBW]

Thanks for that, I thought you would know

 

[ScottishGasMan]

Although, it's worth asking out of interest, what control are you using? Theres probably a programable room stat control that might be worth putting a picture up of, as the boiler may simply not be timed to come on for hot water as its surprising how much hot water demand is met by the solar circuit.

 

[TallulaB]

Thank you for all the info. It's currently controlled by a auromatic 560, which I have the manual for and have programmed it to come on 5am - 9am and then 4pm - 10pm, the temperature is set to 65degrees. We then have a separate Honeywell unit that controls both heating and hot water, again timed to come on at those times. We have tried turning off the water heater via the switch on the wall marked "water heater" in the hope that the boiler would kick in and act as a combi boiler, but nothing happens. The boiler only sounds like it's doing something when the heating comes on.

Hope that all makes sense!

 

[TallulaB]

Attached a wider picture if it's useful

 

[ScottishGasMan]

Thanks, But a picture of the thermostat control is what we would need to see, its where you would turn the heating on and off, normally a little control on the wall in a hall or lounge

 

[TallulaB]

Attached pics of the controls

 

[jeff the gasman]

This could also be attributed to a passing mixer or blending valve.
Worth a punt.