Gravity Fed Hot Water & Heating Wiring Problem

[trainspotter375]

Hi All, Can Anyone help me with a wiring problem. I have a gravity fed hot water system with pumped central heating. Problem is no matter when the hot water on by itself the radiators are also on. My boiler is a potterton flamingo RS35-50 in the kitchen. The wiring is a complete hash of terminal blocks with wires running to the immersion tank and kitchen. The central heating pump wiring runs straight to the back of the boiler! is this normal. even when i get hot water the flow just trickles out of the basin tap. The timer/programmer is a drayton lifestyle lp112 which i have a wiring diagram for but this includes a room thermostat which i dont have. On the side of the imersion is a valve which obviosly directs the hot water to either system, how should this be wired up to the system. app any help, ive included the wiring diagram i have 7 a pic of the valve..thanks all

 

[aggis]

On Gravity dhw & pumped system the pump only works with the heating turned on, for hot water just the boiler fires, so the water in the flow pipe gravitates to the cylinder then cools down & returns to the boiler.
So If the heating flow pipe rises off the boiler we fit a check valve [non-return valve or dunball valve , [different names]] this only lets the heat thro' to the radiators when the pump comes on.
It's probaly stuck in the open position, change it, noting it's orintation

 

[dontknowitall]

For starters, wiring is normal!

It sounds to me as if you have 2 or 3 issues here. I'm sure with enough posting and delay waiting for answers you could fix this but it's probably much less stressful for you to phone a local plumber and ask him to look at it. If you're lucky it could only be a matter of about an hour's work while he's there but if not he should be able to give you an estimate for what is required.

So while we can all talk about live, neutral, earth and so on, it will be, for example, a muddle and difficult to describe the live from the pump or boiler as opposed to the zone valve; and which grey wire to check; and no, you can't see two orange wires, only one; and white wires disappear into the wall; and whether you have a multimeter and what setting to put this on; and have you got a ....

Hopefully you get my drift!!

 

[doitmyself]

I have a gravity fed hot water system with pumped central heating.

The hot water coming out of the taps is gravity fed from the cold water tank in the loft via the HW cylinder. But the boiler water through the radiator and the coil in the cylinder is pumped. This is called a fully pumped system. You can tell this from the valve you have - a Honeywell V4073

Problem is no matter when the hot water on by itself the radiators are also on.

That's problem with the V4073. It is either letting water leak from the pump to the radiators or the valve is being opened to let water through to the radiators as well as the cylinder.

My boiler is a potterton flamingo RS35-50 in the kitchen. ...The central heating pump wiring runs straight to the back of the boiler! is this normal.

It is normal for the Flamingo. This allows the pump to continue running for a few minutes when the boiler goes off, so the boiler does not overheat.

this includes a room thermostat which i dont have.

Get one - they are about £20 for a digital, which is better than the older mechanical type.

On the side of the immersion is a valve which obviously directs the hot water to either system, how should this be wired up to the system.

Presumably you mean the V4073 valve. This can take up three positions: cylinder only, rads only, or cylinder and rads. These diagrams show the pipe layout and wiring

even when i get hot water the flow just trickles out of the basin tap.

That's a completely different problem. Water enters the cylinder at the bottom from the cold water tank in the loft. when you turn the hot tap on the pressure exerted by the water in the cold tank is enough to make the hot water leave they cylinder from the top and through the pipe to the tap. Check that there are no valves on the pipe from cold tank to cylinder or on the pipe coming out of the top of the cylinder. There are two pipes at the top. The one going up into the loft is a vent pipe; that should not have a valve on it. The one coming out from the side of the vent is the feed to the taps.

 

[dontknowitall]

Blimey DoItMyself!! What a great post - about to have my dinner bowl filled but I'll have a good read of that afterwards.

 

[trainspotter375]

Many Thanks Guys For All Your Help especially doityourself, im going to check the actual wiring against your diragram and report back, thank you all again...

 

[mikeygas]

Doitmyself has pretty much covered everything! The only other thing causing your radiators to get hot with the hot water on is a wrongly piped tee, causing reverse circulation. A quick way to check is turn your boiler on for hot water only, wait for a few minutes for it to heat up then feel the flow pipe at the boiler (should be hot, hot) then feel the return pipe at the boiler(should be hot, but not as hot as the flow). If the return pipe is lukewarm and the radiators hot then you know where the excess heat is going.
The remedy is as aggis said and to fit a check valve/non return valve.

 

[trainspotter375]

Hi All, Well have taken a look at the wiring and on the boiler side there is the Neutral Live Earth and the same again N,L, E, which goes straight to the pump. but there is also an extra yellow sw/l {switched live) wire. i have also bought a thermostat so my question is where does the switched yellow wire go? I should have said that the radiators all have thermostatic radiator valves. DoItMyself! can you help with this? where does the switched live wire off the boiler go in relation to your excellent diagram? Thanks again for all your help...

 

[tamz]

The live wire shown on the above diagram is the switched live. It doesn't show the permanent live.
Here is an easier diagram for you showing how it is wired to your boiler.

 

[trainspotter375]

Hi Guys, Thanks all for help and advice, Tamz on the diagrams just so its clear i take it my set up is the one on the left, the Y plan? Also from the 3 way valve what colour wires go to which terminal as i cant seem to identify the colours from the diagram? The 5 colours are blue, grn/yel, ora, grey and white. Obviously the blue goes to neutral terminal 2 and the grn/yel goes to earth on terminal 3 but what about the rest? Also on the emersion tank the cylinder themostat the diagram shows NC, C, & NO but on mine it shows NC 1 & 2 so again which is which? Lastly the frost stat between 1 & 4 my set up hasnt got one of these so do i just ignore it from the diagram..thanks

 

[washer]

Hi

Orange to 4 and white to 7, and ignore the frost stat wiring if you dont have one.

 

[trainspotter375]

Hi Guys, Well i have followed the diagram of the Y plan that Tamz kindly supplied me but it popped the 3 amp fuse so something must be wrong,
Just to be clear from the 3 way valve if ora goes to term 4 and white to 7 then do the blue, green/yel and grey go to 2, 3 and 9 respectfully?
Also my room thermostat i purchased is a sun vic tlx 4101 with the following wiring diagram (see attatched jpeg) how do i wire this to my system?
Last question, my cyn therm has the terminals C, 1 & 2 yet on Tamz diagram it has it as C, NC & NO, again how does this relate to the diagram...please help.....Thanks again

 

[tamz]

As you will already know, you have a L - N or L - E short which is quite easily traced if you have a multimeter. If not you can figure it out. Bet you have put a neutral to the roomstat.

Some basics. I'll try to keep it simple but it may get a bit confusing. It is easier to do than explain but here we go.

C NC and NO stand for Common, Normally Closed and Normally Open and a thermostat is just a switch but most can be used for heating or cooling hence the 2 connections NO and NC.
Common is the live feed to the switch,
Normally Closed is where the contacts would make (join) when the stat is ON (turned up) or there is a DEMand
Normally Open is where the contacts make when the stat is OFF (turned down) or SATisfied.

Looking at the drawing of your stat (the TLX410) it shows the Common as being number 2 (supply to the stat) The switch is shown in the NO or SATisfied position ie OFF (turned down) terminal 3, which is not used in this case.
When the stat is turned up the switch will move to the NC or DEMand position (terminal 1) and allow the power to flow to the load. The Neutral only connects to the load. There is NO neutral on this stat. This is probably where your fault is.

Looking at the drawing i posted earlier and follow the wires.

When the heating is turned ON at the programmer and the HW is OFF, the power will go to terminal 6 and from there to NC on the room stat (this should actually be C, the drawing is wrong but is immaterial as they are interchangable in this instance). When the stat is turned up (ON) the power will flow through the C to the white wire of the 3 port valve, which moves the valve to the farthest CH position and hits a microswitch inside the valve sending the power from the grey (live supplied from HW off from programmer) to the orange of the valve which goes via terminal 4 of the junction box to the Switch live of the boiler which powers the pump and lights the boiler.

Did you follow that? I'd to read through it to make sure i got it right Read it a few times and follow the drawing until you can get your head around it.

If the heating is OFF at the clock and the HW is turned on the live flows from the clock through terminal 8 at the box to the Common of the cylinder stat.
If the stat is OFF ie at NO or SAT the power is flowing to the grey of the valve and nothing happens. Turn the stat up and it switches the power to NC or demand and the power will flow through terminal 4 of the box to the Switch Live and pump.

If you also turn the heating on so HW and CH are on at the clock the motor on the valve will move to mid position and you will get both.

I am not going to go into the internal workings of a mid position valve as it would totally confuse you and you don't really need to know any more than i have told you.

I hope you have followed this lot as i'm off on holiday tomorrow. Someone else will answer you if you are still stuck.

Good luck.

 

[washer]

You might want to think about buying a drayton LWC1 wiring centre, really makes wiring in y and s plans straightforward and easy to fault find on.

 

[fuzzy]

different manufacturers use different codes, so some nc, no and some 1,2,3, youve got to view the actual wiring and work it out

 

[doitmyself]

I think the terms "normally closed" (NC) and "normally open" (NO) are confusing when it comes to thermostats, as it all depends on what you mean by "normally". It depends on the relative temperatures.

If the actual temperature is below the set temperature, the switch will be in one direction; and if the actual temperature is higher than set, it will be in the other. But which is "normal"? From a heating perspective we want the switch to be closed if the actual temperature is lower than set and to open when set temperature is reached.

As for the OP's cylinder stat, terminals C and 1 are closed if the water temperature is too low; and terminals C and 2 are closed when the water reaches temperature.

I should say that I find tamz's diagrams confusing as it does not show the colour of the wires of the mid-position valve: I can work it out as I know how it is wired up. But a real beginner, like the OP will find it impossible.

 

[trainspotter375]

Hi, thanks for all your help, all appears to be working now. just a couple more questions please.

I thought my system was gravity fed, but as doityourself pointed out because it has a honeywell V4073 then i have a fully pumped system so


On the jumper on my timer control which is a drayton lifestyle 112, i have it on "p" for pumped instead of g, is this correct?

Is there a way to check that the 3 way valve is operating correctly? i found this thread on this forum, will the fault finding shown here work on my system?

Doityourself i do agree with you i found the diagram confusing due to the lack of colours on the 3 way valve, can you tell me where they all go so i can double check my wiring..

thank you all again for your help, patience and understanding its greatly appreciated...

 

[doitmyself]

On the jumper on my timer control which is a drayton lifestyle 112, i have it on "p" for pumped instead of g, is this correct?

"P" is correct as you have a fully pumped system

Is there a way to check that the 3 way valve is operating correctly? i found this thread on this forum, will the fault finding shown here work on my system?

Which thread is that?

can you tell me where they all go so i can double check my wiring.

Using tamz's diagram:

Blue to 2
Green/Yellow to 3
Orange to 4
White to 7
Grey to 9

 

[trainspotter375]

doitmyself, sorry, having a blond moment, this thread

http://www.ukplumbersforums.co.uk/central-heating-forum/5316-heating-programmer-question.html

 

[doitmyself]

doitmyself, sorry, having a blond moment, this thread

http://www.ukplumbersforums.co.uk/central-heating-forum/5316-heating-programmer-question.html

Yes those instructions will work. Just remember to reconnect all wires to their original terminals when you have finished - I see I missed that bit out.

Have you checked that the valve is wired correctly as in my last post?

If you are still confused, I can post another diagram.

 

[trainspotter375]

Hi Doitmyself, Thanks for your patience, yes please if you could post another diagram that would be great...thanks again

 

[doitmyself]

if you could post another diagram that would be great.

Hope this helps.

 

[trainspotter375]

Hi All, Well its all Working Fine, The 3 way Valve Cant Have been Connected Up Right Before. As The Water In The Hand Basin Trickled Out But Now Comes Out At Quite A Pace. Also Before When The Hot Water Was On The Radiators Came On As Well Especially The One In The Bathroom Which Was The Closest To The Emersion Tank But It Now Stays Cold Like It Should Do Unless The Heating Is Switched On. Thanks For All Your Help Guys & Girls Who Offered Advice And Diagrams, Looking Forward To Winter Now..LOL

 

[dontknowitall]

Good to hear it's all fixed now and thanks for telling us - all helpful knowledge for the future. I must admit until I read this post I'd have never put poor water flow down to wiring!!

 

[doitmyself]

I'd have never put poor water flow down to wiring!!

It's a complete coincidence. The water circulating in the radiators and through the coil in the hot water cylinder is completely separate from the water which comes out of the taps.