Megaflo Pressure Queries

[nigmac]

Hi,

Sorry if these questions are a bit noddy but I'm in my first house and I was about to bleed my radiators for the first time. I came to this forum to check if there was anything I needed to know when doing it on a megaflo system. Having now read a number of threads I'm quite concerned about my central heating/ hot water.

Some details:-
Boiler - Potterton Promax HE Plus
Tank - HeatRae Sadia Megaflo CL210

The house is about 8 years old, I had the boiler serviced about 18 months ago and following that the plumber replaced the circulation pump. I've also regenerate the air gap twice in the last 18 months (most recently about 3 weeks ago). My concerns below have been happening for the last year at least (I didn't know they were concerns until I started looking in these forums).

Concerns:-

1. Every morning when the heating kicks in there is a gurgling sound from the top floor radiators but when I check them there are no cold patches. (Do I need to bleed them?)

2. The Megaflo details say it has a normal operating pressure of 3 bar, the pressure gauge on mine never goes above 2 and tends to operate about 1-1.5bar.

3. I only have the HW/CH on for an hour in the morning and 4 hours in the evening. Every time the boiler goes off the pressure in the Megaflo quickly (after an hour-ish) drops back to zero.

Any advice you can give me on whether I should be concerned and if so what I need to do is gratefully received...

Thanks

 

[twgas]

The megaflow pressure is seperate from the boiler pressure. If you know how to increase the boiler pressure go ahead and bleed the rads, once done check system is at normal (1-1.5bar)

 

[drbagiva]

Are you sure the gauge you are looking at isn't connected to the heating circuit?

 

[nigmac]

Thanks for your comments.
There is no pressure gauge on my boiler (at least not one I can find), the only pressure gauge is in the cupboard with the megaflo just below the red cylinder.

A bit of an update from me. I have no real issue with the pressure of the hot water in the house, the taps and the showers are fine.

Last night I bled three of the five radiators on the top floor, one of them immediately dripped water (i.e. no air), the other two let air out but then the air stopped hissing and no water started to drip so I closed the bleed valve.
I assume I've done something wrong?

Interestingly the radiators didn't make a gurgling noise this morning (or at least it didn't wake me like it has for the last few weeks).

The main issue/concern I have is that the pressure in the megaflo system is between 0.5 and 1.5 when the heating/hot water is on but within an hour of the heating/hot water going off it drops back to zero. Is this normal (as the advice sticker on the side of the tank says operating pressure 3 bar)

 

[DrPlumb]

If its a red expansion vessel then it's for the heating, the megaflow has a built in expansion air gap at the top (I'm assuming you know this as you know about regenerating it?) therefore the pressure gauge relates to your heating system pressure and is nothing to do with the megaflow. To start, I'd say top the system up via the filling loop, bleed all rads and refill to 1-1.5bar when cold......and keep an eye..... If the pressure drops out, maybe you have a leak or the prv (probably under the red exp. vessel with the gauge) is letting by slightly? A couple of things to check for starters

 

[CBF]

+1 on above

 

[nigmac]

Many thanks for your suggestions, I tried to add pressure into the system but as none of the valves were labelled I wasn't sure which one to use and none seemed to work.
I got a plumber to come in and service my boiler (it needed it anyway) and he showed me the right valves to open (it turns out I needed to open two). The system is now at 1.5bar and the issues seem to have gone (although it's only been 24 hours).
Thanks