Hot water water running out of Megaflo

[nickel-metal]

Hi,

So i have come across this forum and it appears to be incredibly useful however no instance seem to cover the problem I am facing right now in entirety.

As per the subject, I have a 300i Unvented Megaflow tank which runs out of hot water incredibly quickly and most frustratingly even when the hot water is not being used. I have diagnosed that the hot water outlet pipe is continually flowing and subsequently the cold water inlet is continually filling the tank with cold water. No hot water is being used any where and I have not been able to find a leak. This is obviously the problem, however I am now stuck. Hot water runs to ice cold in 60-75 minutes.

I have turned off the hot water outlet and the cold water stops feeding the tank. I initially thought I must have a leak. Nothing is visible.

I know there can be issues with mixers inside taps and showers. I have Hansgrohe showers mixers and taps fitted around the house. Everything is approx 3 years old. If the hot water is bleeds into the cold water, this could be the problem. I have tested this to no avail, switching all the taps to cold and also turning the hot water feed off below the sinks, problems persist. For the showers, the only option i currently have is turning the dial all the way to cold, I can not isolate the hot water feed for these (plumbing inside the wall). Nothing I have tried has stopped the flowing hot water from the outlet pipe.

I am now wondering could there be a problem with the Megaflo that could manifest this issue, before searching for the leak again? The turdish drips a bit of water and I have replaced the air expansion bubble. Could the 3bar pressure reducing valve cause this problem if faulty? My understanding could be flawed, but if the PRV wasnt working then could this be creating extra pressure in the tank and forcing the hot water to circulate around the house? I have a bronze water pump which is connected to the hot water inlet however I have never really used it and this also appears like it doesn't work now. I am currently discounting the bronze pump as the problem.

Hope someone can provide me some guidance to isolate the problem.

 

[jeff the gasman]

You have a leak mate.

 

[stardanny]

You need a G3 plumber to look at your megaflo and service it.

Is there a isovalve on hot outlet of the cylinder? If yes, turn that off and turn off hot water return if fitted.

Check the tundish again, see how much water is coming out.

Have you got concrete floors? Maybe pipes under is leaking?

Daniel

 

[nickel-metal]

Yes, spoke to megaflo service guys at baxi and they said they would come out on a no fix no fee basis. So no harm in doing that.

Leak, yes possibly. But can't for the life of me figure out where it could be. I have a concrete floor but the hot water circuit does not go there. Possibly in between my wall, that will honestly be a nightmare to deal with.

I do have isovalve on the hot water outlet but not on the return circuit. The pump on return looks like it's packed up too. So that doesn't help. But pretty sure that shouldn't make a difference. The water from Turdish is slight in comparison to the cold water flow into the tank.

Cheers for the responses.

 

[jeff the gasman]

You said mains water is coming through the inlet! Where is it going?
Absolutely simple. You cannot compress water.
Did you miss a few days off school?

 

[nickelmetal]

Yes Jeff, I agree.

The water is coming in through the inlet and the hot water is leaving the tank. If I stop the hot water with the isovalve the inlet water flow also stops. I know where the issue is pointing.

I also have a water meter which seems to be flooded at the moment otherwise I would simply review the water meter to prove the water is leaking out somewhere but no evidence inside the home. I'm still hoping that it's one of the mixers in the wall, the thermostatic catridge would be easy to replace, but haven't figured out how to isolate that issue yet. simply leaving it on cold or hot doesn't resolve the issue.

 

[Agile]

You seem to have a leak in your meter chamber for a start.

Water leaks are simple compared with some boiler issues.

Why not engage a pro?

 

[jeff the gasman]

YOU HAVE A LEAK, CAN YOU HEAR ME.?
If not, YOUUUUUUUUUUU HAVE A LEAK.