Mega flow temperature variation throughout house

[craigjm]

One of my properties has a mega flow water heating system. There is no gas in the property. It’s about three years old. Just been informed that the water in the bathroom is not coming through very warm. The bathroom is next to the cupboard with the mega flow. The strange thing is the water in the kitchen and the guest toilet downstairs is much warmer. The water in the bathroom is Luke warm in the sink, bath and in the shower which is a mixer shower. Any idea what would be causing that especially as the mega flow is in the cupboard next to the bathroom so has further to flow to get downstairs. Looking for some hints before I book a plumber

[Nnnnnnnn]

The bathroom might have an anti scald valve fitted as the hot water enters the bathroom. I would trace the hot water supply if it’s back to back with the mega flow

[craigjm]

Nnnnnnnn said:

The bathroom might have an anti scald valve fitted as the hot water enters the bathroom. I would trace the hot water supply if it’s back to back with the mega flow

Good shout. Why would it suddenly be making itself known though and not three years ago when the bathroom and mega flow was fitted?

[chrismoose91]

Mixing valves can and do fail over time. They have strainers that need cleaning, the valve itself can scale up.
They fail safe to cold and if the cold water supply stops, it won't let any hot water through. They shouldn't anyway...

[Regbuser]

Plus, you may need to recharge the air gap in the megaflo cylinder. Plenty of YouTube vids show how to do this.

[craigjm]

Thanks guys