need help with megaflo hot water tank..

[paul4xxxx]

since being installed we have never got "hot" water from this tank..

both imersion heaters work fine and heat up to "warm"

flow and return pipes from the boiler are boiling hot. and the valve on the outside of the tank is open.

i have pushed the red re-set button a million times anb adjusted the temps but this doesnt do anything.

has anyone got any ideas??? surely if the flow and return pipes are both piping hot, we should be getting hot water? but even after 5 hours its still only warm

 

[lilleville]

Hi Paul. When did you have it installed? And does it have a separate expansion vessel?

 

[paul4xxxx]

its acctually been installed for over 3 years, but we have never really been bothered about it, it has an expansion vessel. its the 300ltr tank i think. nearly 2m tall.. all the readiators heat up fine, its just the hot water that does not

 

[wetshoes]

Have you tried turning temperature on immersion thermostats up a little?
Can you post a photo of cylinder showing how the pipes are configured ?

 

[paul4xxxx]

with all the lagging we have fitted there is no way to make sence of the pipes.. surely if both the flow and return pipes get piping hot there wouldnt be a problem with the piping though. i may be wrong. but i hope i'm not

 

[lilleville]

What make is it? It might be a good idea to call the manufacturer to see if they can shine light on it. My initial reaction was air in the cylinder if it had an internal air bubble which needs reinstating. Are you sure the separate vessel is for the hot water and not the heating? Is it red or blue?

 

[paul4xxxx]

its a megaflo tank. the expansion vessel is red and connected to the whole system (water and heating) there is just 1 outlet on the boiler and 1 inlet.. they feel 2 heating zones which heat up perfect. and the hot water. which only gets warm

 

[lilleville]

It does sound to me like the air bubble inside the tank needs reinstating. To do this you need to turn off mains iso valve, then go downstairs and open up the hot tap in the kitchen, leave it open and go back up to the cylinder and hold open the p&t valve on the side of the cylinder for about 15 minutes or until it stops glugging. Then when you've emptied it enough go and turn the hot tap off and turn the mains to the cylinder back on. See how that does.

 

[paul4xxxx]

the hot water tank is downstairs, and we have a secondary return fitted. how would i go about it in that case???

 

[lilleville]

Turn off the mains isolating valve and connect a hose to the drainoff, drain to outside or if in a basement then into a bucket / drain. Open the drainoff valve and hold open the p&t valve for about 15mins. Then close the drainoff and open the mains valve again and let it refill.

 

[paul4xxxx]

i shall give that a go tommorow then i just went to the tank before i got your reply and help open the t&p valve with the main feed off until the water stopped running. will see if that woked, if not i will do what you suggested

cheers for the help

 

[lilleville]

No worries, its great to be useful! Hope it works, let me know.

 

[WDIK]

there is no external expansion vessel on a megaflo it uses an internal bubble