Megaflo tank little or no pressure

[sups]

Hello,
Yesaterday morning I noticed a condsiderable amount of hot water pressure drop from the taps. In the evening when I got home from work I tried to regenerate the air gap according to the instructions, but instead of the gurgling I had hot water flowing through the turndish, I didnt think too much of it and carried on holding the release valve for a few more minutes.
Then when I tried the hot water tap, there was nothing flowing, it was like there was no pressure in the megaflo tank. A builder friend reckons that the tank pressure only works when the water inside is hot (I didn't think it works like that) .I turned up the temperature a little and I started to get a little bit of water at the taps, still far from normal though.
Another thing is that I can hear a very low hissing noise coming from the in flow pipe, it's a bit like the noise you get from a pipe when the tap isn't closed properly and there is some water dripping. When I turn off the megaflo inlet isolator valve (which is on the same length of pipe) the hissing stops.

I don't ever remember hearing this noise in the past when the system was working correctly.

This together with UFH wo's is driving me a bit crazy.

Any advice appreciated.

 

[picasso]

Have you have mangled the plastic stop tap, take it off and use a spanner to turn the valve fully back on, there is also a filter in the cold water inlet that might be blocked.

 

[ianmcd]

but instead of the gurgling I had hot water flowing through the turndish, I didnt think too much of it and carr

on holding the release valve for a few more minutes.

you have to hold it open until the water stops , can sometimes take a while.

A builder friend reckons that the tank pressure only works when the water inside is hot (I didn't think it works like that)

Total rubbish

You would be better getting a G3 qualified heating engineer in to sort your UFH problem and you UHW cylinder problem, your cylinder is supposed to be serviced every year

 

[sups]

Have you have mangled the plastic stop tap, take it off and use a spanner to turn the valve fully back on, there is also a filter in the cold water inlet that might be blocked.

Thanks picasso.
The tap handle does a solid quarter turn.. didn't feel it slipping off the teeth of the nut.. but a valid point.. I'll go home and check

Your second suggestion is a bit more valid... I called up megaflo tech support (I didn't know they had tech support for us regular consumers) and described the symptoms, the chap said that it sounds like water is not flowing into the tank properly because of some sort of blockage, the hissing sound seems like a small amount of water making it past the blockage, all signs point to either the stop tap, or the valve next to the stop tap.

I've arranged a Baxi engineer (££££) to come and take a look and fix if possible. I'll report back with what happens.

 

[sups]

@picasso you were on the money!..just after the cold water inlet tap there is another pressure reducing valve. The engineer came and replaced it
All working fine now.

Thanks