central heating/water timer

[johnston1991]

hello all,

iv been asked to replace a broken central heating and water timer by a neighbour, i got round there expecting to just have to do a new for old swap, i found the old timer unit and also an old 8 pin optical relay ?:| i have no idea with this kind of thing and was just looknig for asdvice on what i should be repacing the timer with

i have taken some photos..

http://i189.photobucket.com/albums/z136/johnston1991/PICT0380.jpg

http://i189.photobucket.com/albums/z136/johnston1991/PICT0385.jpg

http://i189.photobucket.com/albums/z136/johnston1991/PICT0386.jpg

The Two fused spurs are nothing to do with the the boiler/pumps

any help of advice would be appreciated

thanks

 

[jl-heating]

i would just re wire it completely,its just a 5 core from the clock to the 10 way.

any programmer will do i usually use honey for reliability.

not sure what an 8 way optical thing is though lol.

assuming an s plan here

assuming y plan here

 

[johnston1991]

Hi thanks for the reply iv looked through the diagram but we have the hot water on one pump and the heating on another ?

Many thanks

 

[jl-heating]

is it a 3 port or 2 port valve ? i will find a specific 1 for you thats clearer.

sorry better diagram here with a more up to date programmer honeywell st699

The ST699 time control programmer can be used as a replacement programmer on gravity primary or fully pumped systems. The ST699 has a proven easy to use design. The front panel of the programmer will fit to the same backplate. Programming the timing sequence is straightforward, using the top slider switch and [+] and [-] buttons. Please note it is recommended that, in order to comply with Part L1 Building Regulations central heating systems should be upgraded to fully pumped with a fully independent programmer e.g. ST9400C.

which can be found here.

 

[NozSpark]

I had a CH system (2 x flow & 2 x return), both pumped in my last house. The boiler was moved and the gravity loop wasn't very effective. There were no valves fitted....

What I had to do is wire the outputs from the controller (via thermostats) to the respective pumps and also to two relays which would fire the oil burner, this would allow me to have either HW or CH / or both at the same time.

If looks like you have something similar, but with only 1 relay... I think that this would allow you to have HW or CH & HW (not as flexible as my setup was)...

If you want I could knock up a rough diagram..

 

[johnston1991]

hii thankyou both for the info havent been able to get on here for a while computers ..

as far as i know there arent any valves ? theres the boiler then 4 pipes away a pump on each out going feed, one for ch and one for water i persume..

and yee that sounds similar to what they have, would you mind?

cheers

 

[batty]

What is actually wrong with the programmer are you sure it is not the relay that has gone wrong.

Batty

 

[johnston1991]

hi, urm apparantly the nieghbours husband was a spark, and its been broke for some time but he fell ill and never made it to sort it or something?

the programmer do power up but doesnt do much else, iv checked the relay and it switches ok

thanks

 

[Andy™]

If you take that one off the wall you will find a diagram on the back of it. wire new programmer in the same way and your done

 

[johnston1991]

only problem is when the timer broke because of the situation somebody changed the wiring to bypass the timer :S

since then they have been controlling the boiler manualy and having the pumps run flat out 24/7

 

[Evans Electric]

Surely you have a home made system there, I think you need to follow the wiring , draw it out and match it up with the heating system , which could also be a DIY jobby.

 

[johnston1991]

ye thats sounding like the best idea take the lot out and start clean,so one of the timers above with the help of the doiagram with two relays should sort out nicely,

cheers everyone

 

[jl-heating]

so no room stats or cylinder stats ??

you basically want the timer to run each pump seperately and independantly ??

i have never seen a setup like that ?? never seen 2 pumps on a system ..

to do the job right i would upgrade the controls (plumber) and fit a y plan and just 1 pump. anything else is wasting your time and throwing money away.

you might as well throw away the timer and put plug heads on the pumps and plug them in when you want heating/hot water.

 

[johnston1991]

urm i will take a picture tomorow, there is a room stat in the hallway sorry, but ye a pump to the left of the oil boiler and a pump to the right and then the two returns below it

not good then?

 

[jl-heating]

if thats all you have to work with and the customer wont budge on the upgrade you would have to look at as 2 systems,ie fit the timer ..

L-N. and i think 3 for htg on and 5 hw on.

so 5 core to the 10 junction box from timer,(park the earth)

htg first to 4 in connector 3 core earth to room stat using LNE and SL return to 5 and pick up the heating pump L

hot water same. from timer to blocks pick up on 6 and connect to pump L.

what i cant figure out is how to pick up the boiler, if you connect on both 5 and 6 it will bring on both pumps when the timer calls for heat or hot water.

 

[Andy™]

what i cant figure out is how to pick up the boiler, if you connect on both 5 and 6 it will bring on both pumps when the timer calls for heat or hot water.

by using relays...

 

[jl-heating]

i would strongly advise to cut of one of the flows pipes from the boiler and fit a y plan then wire as normal it would stop cross circualtion and work a lot better also strongly advise a cylinder stat to comply with part l and also save some cash

 

[jl-heating]

by using relays...

give me a link andy how do they work ? they may come in handy with under floor whan i add a couple of circuits i always seem to struggle and they will come in handy.

also would it allow both circuits to run side by side ?

 

[Andy™]

give me a link andy how do they work ? they may come in handy with under floor whan i add a couple of circuits i always seem to struggle and they will come in handy.

as an example

If you had 2x pumps needed to run independently, but a boiler to fire when either or both was on, you can use 2x SPST relays.

connect a relay in parallel with each pump, so that when a pump becomes live, a relay switches. connect feed to boiler in parallel with both relays, so when either is on, boiler fires, but more importantly, one relay switching on will not turn on power to other pump.

you can connect as many relays this way as you need, and you can also connect stuff so that if one switches in, the other cannot

cant be bothered to make you a diagram now (partly too many variables to make an accurate diagram), but if you ever need it, either make a new thread or PM me with what you want it do and ill sort a wiring diagram for you

so much easier with DC controls, just stick a diode in there and your done

 

[jl-heating]

http://www.the12volt.com/relays/relays.asp

like a solenoid on a spot light ?