Room stat understanding

[muffinman]

Right
can somone give me a understand of room stat wiring, so far at work and at college i have been able to blag my way thought it. its a topic that i dont like and will be one of my weekness if i dont come to terms with it can somone please explain a bit about it

many thanks

 

[lame plumber]

always fit combis and a 2 wire combi stat, its that simple

 

[muffinman]

that would be the idea world but say for instances you have a 3 storey house, you have a unsuite on the secound floor, and you have 1 unsuite on the first floor with a main bathroom as well. on the ground floor you have a ultitly room with a washing machiene that need a hot and cold feed. and you need to zone each floor off to comply with building regs also the customer would like underfloor heating in kitchen and bathroom. your combi with your 2 wire stat isnt much use here.

 

[AWheating]

Don't matter what the system is. A room stat is a switch, it requires a voltage to it and to be able to send voltage back from it. Most controls are just a movement of electricity around a circuit through some switches in a certain sequence.

 

[Killy Bing]

Logic and practice will give you the understandng.

as you pull out pieces keep them and wire them up in your spare time.

i made up a board with a pump, 3 two ports, a two port , cyl stat, two room stats, wiring centre, lightbulb to represent the boiler.

Got honeywells wiring diagrams and practiced.

i also made a power point up witht he wiring so i could logicly do it myself.

Get yourself on the honeywell and danfoss wiring courses.

 

[muffinman]

Don't matter what the system is. A room stat is a switch, it requires a voltage to it and to be able to send voltage back from it. Most controls are just a movement of electricity around a circuit through some switches in a certain sequence.

ok what about a 3 wired stat how does that work, and also if a room stat has a battery it doesnt need a neutral ?

 

[kris]

Hi there muffin man I found the easiest way to understand the motorised valve myth was to draw a flow diagram of where the direction the voltage was traveling like awheating says its sequence of events ie start at fused spur then onto clock etc but the wiring diagrams you get with the zone valves n stats should help,, whats tricky if a spark has done it there own way using wrong wires the way they want can be very confusing,,,

 

[kris]

think of a stat like a light switch you have your common then you have an on and an off its simply if its allowing the electricity to pass through

 

[muffinman]

think of a stat like a light switch you have your common then you have an on and an off its simply if its allowing the electricity to pass through

so your common is always there ?

 

[kris]

Just curious muffin man but what year are you in at college that they are askin you guys to wire the stats ??

 

[muffinman]

i am in my first year of apprenticeship domestic, but have been working with plumber for 4 years now. my boss sends me out to job by myself and i should have complete the apprenticeship course in the next 6 months if the tutor pull his finger out of his arse. my boss is going to be putting me on my oftec course hopefully in the next month. at the moment the main thing i am struggling with is wiring a room stat. sound odd i know but i cant get my head around it :/

 

[kris]

Im not following you if you are in the first year of apprenticeship how can you be finished in 6 months ,,, please dont think im being cheeky its just electricity and gas should only be messed with people who are competent and qualified to do so,,, if you are in first year of apprenticeship then you shouldnt be wiring stats muffinman

 

[kris]

You should approach your boss explain to him what your having difficulty with and ask him for guidence or your college lecturers will help

 

[muffinman]

you dont need to be gas safe to wire a stat. as far as wiring goes i would say im competent. im just struggling with wiring stats. and the plumbing apprenticeship is only 2 year. ive done 1 year.

 

[muffinman]

You should approach your boss explain to him what your having difficulty with and ask him for guidence or your college lecturers will help

yes i will but i just wanted to see if this forum would be able to help me out

 

[Killy Bing]

Which part dont you under stand exactly?

i'll whip up a diagram for ya

 

[muffinman]

Which part dont you under stand exactly?

i'll whip up a diagram for ya

i don't understand common, and then why you have 2 other wires

i take it that common is always there but why?
and then why do you need 2 other wires.
and if you have a stat that has battery's you don't need a neutral

 

[Dotty]

i don't understand common, and then why you have 2 other wires

i take it that common is always there but why?
and then why do you need 2 other wires.

Look at it in terms of water. you have a hose from a tap going to a valve which will send water one way or the other. This hose is the COMMON hose (wire). The valve normally sends water up another hose to point a. In this position this side of the valve (switch) is NORMALLY OPEN. The hose going to point b has no water unles the valve (switch) is operated. This side is NORMALLY CLOSED.

and if you have a stat that has battery's you don't need a neutral

Shouldn't have any wires to it.

If you've a live you always need a neutral.

 

[muffinman]

so the common is always there.
so the programmer send power to the room stat, (the room stat is a switch between the programmer and the motorised valve.

the common is a netural?

 

[muffinman]

and if the room stat has battery then it doesnt need a netural becuase the netural is the common which is already there ?

 

[Dotty]

Ignore the neutral for now.

As i said, think in terms of water, if you do that the neutral would be the drain......

 

[muffinman]

Ignore the neutral for now.

As i said, think in terms of water, if you do that the neutral would be the drain......

ok i think i have got it.

 

[AWheating]

you only need a neutral if there is something inside the stat that uses a current (needs a circuit/flow or leccy), like a display or an anticipator resistor. mechanical stats that requre a neutral have this type of resistor inside to make them work alittle quicker/better.

you need an earth if the stat has any exposed metal parts or a metal back box, its always best to run an earth just in case.

you should note that the cpc inside a twin and earth can not be used to carry current.

 

[AWheating]

it should also be noted that some wired stats/programable stats also have batteries.

 

[muffinman]

it should also be noted that some wired stats/programable stats also have batteries.[/QUOTEa
and if they have a battery they dont need a netural?