Help me decipher my boiler/heating system?

HungryHippos · 1 Jul 2017 at 16:24

Just got a new house, and unlike my old one, this has a more complex system.

My previous one was a simple combi-boiler, with dual zone thermostats. Need hot water it just fires up. Need heating, it fires up for that automatically as well.

Here are some images from my new one:

http://imgur.com/a/7z9Nm

It seems to have a Potterton condensing boiler, in pics #1 and #2.

Pic #3 is a Honeywell control unit with model ST9100C.

Pic #4 is one of the two Honeywell CM907 thermostats (one upstairs one downstairs). This looks reasonably similar to my old zone thermostats.

Pic #5 and #6 are of the bit water tank in the cupboard upstairs.

Could really use some help understanding how this all interacts!

I'd guess for hot water, the big tank is used upstairs. I think there is a smaller tank above it that may be for a smaller heating load. Does the hot water tank need the boiler as well, or does it just use electric to heat it?

I'd assume the condensing boiler is crucial to heating, but the water being used by the heating would not be drawn from the big water tank?

HungryHippos · 2 Jul 2017 at 16:48

Thanks guys, I took some pics of the tank above the cylinder.

http://imgur.com/a/wsc1X

Sorry for the first pic, my camera sees the light above as the same lumens as a thousand suns, but you should get an idea where the tank sits in relation to the cylinder.

HungryHippos · 2 Jul 2017 at 23:40

Thanks guys for all the help, so if my understanding is right from all that has been said here:

1. The boiler has it's own control unit, that controls when it comes on for hot water. It will then heat the water that gets stored in the cylinder and is drawn from the cylinder when you use hot taps/showers/central heating etc.

2. The cylinder has it's own immersion heater in case the boiler is busted, but one assumes it's not used generally. Is there a way to confirm that if the immersion heater is in use or not? I assume it's reasonably expensive to run compared to the condensing boiler. Maybe even a way to disable the immersion heater so I know it can't use it without my implicitly turning it on?

3. The thermostats will use hot water from the cylinder, but wont directly "ask the boiler" to heat water like my old combi did? In that case I'd assume it would be best to program the hot water to come on an hour or so before you intend to put heating on?

Probably missed some understanding on the above.

HungryHippos · 3 Jul 2017 at 23:04

Not moved in officially yet, main furniture is moving across this weds, just wanted to get a handle on how it was working before I needed to use it. Won't really be using the heating for a while as well as it's still pretty warm out there.