Megaflow prob...Ithink

[Durgo]

Hello all!

Central heating (sealed system) loses pressure. I can't find any leaks so...
could it be the indirect megaflow? Can't get the customer to leave the hot water alone long enough to eliminate it that way - besides wouldn't the CH and megaflow balance themselves if they had become one system?
I bet the answer is really simple right....?

 

[Durgo]

how could the coil be leaking cos the pressure inside the tank is greater (3bar)than the CH (2bar) hmmm

 

[oilman]

The Megaflo is the least likely problem. It's more likely to be no expansion space, or a microleak. Try doing a pressure test on the heating system..

 

[Durgo]

I thought about a leak - if it was really slow ("microleak"), the pressure wouldn't be dropping as quick as it is (from 2bar to 1bar 24 hours after topping up. If the system is loosing that much water, that quickly your bound to see something.....I dunno. If it was an exspansion prob would't it be discharging through the shared tundish? its all dusty and doesnt look like its been wet.....I dunno though...faulty guage maybe

 

[croydoncorgi]

I've got two of these at the moment too - fortunately neither my original work! Wretched things lose pressure from 1.5 down to .75 Bar over a week or so. In one case its a posh first-floor flat with an even posher one underneath but no ceiling evidence yet! The other is a house but unfortunately with pipework buried in the floor screed - again with no evidence yet appeared. All very difficult!

In your case if it's a reasonable sized system, 2 Bar down to 1 Bar in 24 hours means that several litres of water have gone somewhere! As others have said, the UVHW system is an unlikely cause: the pressure inside the tank is HIGHER than 1 Bar (I assume - mains water pressure is ?, PRV reduces is to 3 Bar usually), so if there was a coil leak, system pressure would rise!

At the rate of loss you have, there might be a slight 'leak noise' that could be detected, especially with the pressure raised to 2.5 Bar. There's a sound0sensing gadget used by water companies to locate leaks in street mains - there MIGHT just be an equivalent for house-scale plumbing. If someone has access to such a thing please let me know too!

 

[blahblah]

I think its the 'Awmygawdwotwuzdat' by a firm called E R Hole. Usually only sensitive to rather loud and gushing sounds but particularly good with unnerving drips!

 

[tech]

Is the boiler a system boiler if so ,maybe the prv located on the boiler is leaking.

 

[Durgo]

prv located on exspansion vessel by megaflow. not the culprit....
thanks for your ideas everyone.