I'm just moving to a house here in the UK with a private water supply, it will need a UV upgrade to meet current recommendations.

 

My understanding is that the UV is permenantly on and typicaly the bulb lasts 12 months (9,000 hours).

 

This particular system has a pressurised vessel to reduce strain on the borehole pump.

I did some basic tests and could see that the pump controller worked very well at maintaining pressure (as seen on the gauge). If the presure dropped to 3bar, the pump kicked in and raised it back to 4bar, then went off - hen repeat as required.

 

Would it not be possible to link the UV lamp to the borehole pump controller, so its only on while the pump is pushing more water into the system? Even if the UV stayed on for 30 secs after the pump stops, to take care of any residual flow)

I could even install a timer of some kind, to monitor the UV lamp run hours.

 

Thoughts?

Sorry it makes no sense, the UV light is last thing in the system. Pump start logic is a lagging indicator, as pressure vessel is the supply, the pump tops up the pressure vessel.

 

You are over thinking, they are designed to stay on, not switch on off a few thousand times a year. You will pay more for bulbs and monitoring than you save in energy. Plus there is a heat up time, as it requires to heat mercury to emit the UV light.

 

 

Thanks, that makes sense. I was thinking about UV bulb life (and cost), plus of course the electricity cost.

 

I will scratch it from my thoughts  

On 16/09/2024 at 14:20, Kuro507 said:

I was thinking about UV bulb life (and cost), plus of course the electricity cost.

 

Have wondered about this in the past. I think our UV lamp is more or less instant start but even so the complication of avoiding any let-by was too difficult.

 

Admittedly ours is a second home but I certainly don't change the lamp every year. In fact have done it once in 17 years as a precaution, old lamp was not discoloured and no obvious reduction in light level so kept as a spare. Managed to break the thin quartz sleeve £££ when I did it so am not in a hurry to do it again. Rubbish Pentair design as there is no proper clip so relies on connector supporting the weight of the lamp.