How does my heating system work?

[horsebox]

I need to fix my mothers heating so the first step is to figure out how it all works. I know very little about plumbing or heating systems but I've wanted to learn for a long time so nows a good time to start. Firstly she has this thing installed in her shed:

^^ Its a Vokera Mynute HE (can't find the model number)
and she tells me thats the water heater but whats confusing me is theres a hot press in the upstairs bathroom with a big cylinder in it. I always thought those things are what heat the water so I don't know whats what here.

Anyhow 1 problem I've spotted is that the pressure on this contraption in the shed is at 0 bars and I need to bring it up to at least 1 bar but the instructions in the manual are to:

- Locate the filling valve connections (usually beneath boiler, see fig 3)

- Attach the filling loop to both connection.

- Open the filling valve slowly until you hear water entering the system.

- Close the filling valve (on the boiler) when the pressure reads between 1 and 1.5 BAR

the main problem here is I don't know what the filling loop is and can't locate the filling valves cuz the diagram they provide is terrible. There is a valve underneath this contraption that I can turn by hand but I tried turning it while the machine was on and the temperature output reading started dropping but the pressure didn't rise at all. Thats obviously the gas valve. I rang the phone number written on this thing and the guy on the other end told me that the filling loop is in the hot press. Now I'm getting confused. Whats the purpose of this big cylinder in the hot press? Does that thing just hold the hot water while the machine in the shed heats it? The machine in the shed is gas powered and according to the manual its purpose is to heat water and deliver to the pipes in the house but if thats the case then what is this big cylinder in the hot press for?

 

[rfdevere]

Well i must say - my advice i'll give you is for informational purposes. You will be breaking UK laws to open the 'Machine' - Combination System Boiler up and this could be dangerous on so many level. For the time being lets look at these steps and see how you get on ok.

1. The 'machine' has a sensor in it that will stop it working if the water pressure in the pipes drops bellow a certain amount - like what your has.

2. The water pressure has dropped because there is a leak in the system - for the time being ignore this as it might only be a tiny leak or it might just be a system design fault.

3. the 'filling loop' refers to the section of the system (anywhere on the system) that has 2 things:
1. A cold feed pipe 2. Part of the heating coil loop.
The filling loop itself is just a small metal hose that runs from the cold pipe to the boiler loop to fill it up (pressurise it)

4. Fill the system up to 1.7 bar COLD and see if you can reset the 'machine' by using the reset instructions in the manual.

5. If this doesn't work PLEASE CALL A PLUMBER it will be cheap and save you all the hassle.

6. the tanks in the bathroom connect to a gravity fed hot water system coming from a tank in the loft. this tank is where your hot ware is stored. the 'machine' has two loops inside one is for the radiators and the other is for the coil inside the hotwater tank.

Google the following "combination boiler filling loop, Gravity fed hot water diagrams and system boilers"

Good luck