central heating help needed

greenore

hi,

system has 2xCH & 1xHW Zones

system also has solid fuel back boiler

system has 2x CH Motorized valves

Garage = Oil Boiler & Pump (No over-run)
Hotpress = Cylinder, 2 motorized valves, CH circulating pump & Back boiler pump, cylinder stat, back boiler stat

so there is 3 zone time clock (2x CH & 1xHW)
2 CH room stats


what i need to happen:
CH1 turned on = fire Boiler + pump(garage) & Circulating pump (hotpress) & open corresponding "MV"
CH2 turned on = fire Boiler + pump(garage) & Circulating pump (hotpress) & open corresponding "MV"
HW turned on = fire Boiler + pump(garage)
Back boiler when lit = opens both CH motorized valves & fires Circulating pump(hotpress)

I need a wiring diagram for this system

if you could be so kind to help me out i would be forever grateful

Sir Arthur Daley

Has this system a single or dual coil cylinder?

Diggerdunne

you need to use 2 or 3 relays so that the back boiler won't come on at the same time as the oil boiler. it basically stops back feeds thru switch wires. i think there have been diagrams posted for this before if u do a search

Sir Arthur Daley

Diggerdunne wrote: »

you need to use 2 or 3 relays so that the back boiler won't come on at the same time as the oil boiler.

Why cannot the 2 systems run together?

Diggerdunne

why wud u want the 2 systems running at the same time???

Sir Arthur Daley

Diggerdunne wrote: »

why wud u want the 2 systems running at the same time???

Its not a matter of preference, one has to have an installation where the two can potentially run together i.e when a home owner comes home from work turns on oil and after a period of time lights stove.

tomdempsey200

you can buy a wiring unit that will allow the oil and solid fuel to work together

Sir Arthur Daley

tomdempsey200 wrote: »

you can buy a wiring unit that will allow the oil and solid fuel to work together

As long as the plumbing installation is plumbed correctly.

K.Flyer

Your solid fuel back boiler does it heat hot water only or hot water and radiators?

Sir Arthur Daley

K.Flyer wrote: »

Your solid fuel back boiler does it heat hot water only or hot water and radiators?

From op.

Back boiler when lit = opens both CH motorized valves & fires Circulating pump(hotpress)

tomdempsey200

Sir Arthur Daley wrote: »

As long as the plumbing installation is plumbed correctly.

the plumber has to tell the man wiring the system how it will operate

he is usually the designer of the heating system on domestic work

Sir Arthur Daley

tomdempsey200 wrote: »

the plumber has to tell the man wiring the system how it will operate

he is usually the designer of the heating system on domestic work

Very true, I have however had unrealistic demands by plumbers in certain installations, its fine for a plumber to slap in a shot of motorised valves, pumps and stats and say this is how it should work now go away and wire it, i refused on a couple of occasions as the way the pipe work was done was a train wreck along with all the MVs.

K.Flyer

I.M.O. Any plumber or heating installer worth his salt should be able to design the wiring diagram for the system.
Unfortunately some plumbers feel its the electricians responsibility, when its not!

@ Arthur, thanks, missed the last line.

@ O.P., I recommend that you get a good plumber who understands heating control systems to check over your system to ensure it is suitable for the changes you want.

Sir Arthur Daley

K.Flyer wrote: »

I.M.O. Any plumber or heating installer worth his salt should be able to design the wiring diagram for the system.
Unfortunately some plumbers feel its the electricians responsibility, when its not!

Good point, imo a plumber should give detailed electrical plans for a system as often the electrician gets the blame for a system running incorrectly.

2011

Sir Arthur Daley wrote: »

Very true, I have however had unrealistic demands by plumbers in certain installations, its fine for a plumber to slap in a shot of motorised valves, pumps and stats and say this is how it should work now go away and wire it, i refused on a couple of occasions as the way the pipe work was done was a train wreck along with all the MVs.

What do you mean by "unrealistic demands" ?

As already suggested the control philosophy should be dictated by the plumber. If the system irequirements are complicated my advice is to get the plumber to write them down so that they can be referred to later.

Sir Arthur Daley

2011 wrote: »

What do you mean by "unrealistic demands" ?

Having several motorised 2 or 3 way valves and pumps and stats and having them do what the plumber asks. When on asking the plumber then how will i wire this he just shrugs the shoulders and says im not the electrician.
Just because a plumber fits lots of motorised valves etc into an installation does not make it correct from his point of view.

Ill give you an example i had a house like in the op case, the plumber very inexperienced as was found out, he had 9 motorised valves and 4 pumps fitted along with various stats which he wanted to control various zones.
I took one look at the system and said straight out i wont wire that, not alone from all the unnecessary auxiliary equipment but because he had a pump fitted to the gravity hw circuit from the solid fuel along with other small issues. Wouldnt i be the nice boy wiring up such a case?

tomdempsey200

Sir Arthur Daley wrote: »

Having several motorised 2 or 3 way valves and pumps and stats and having them do what the plumber asks. When on asking the plumber then how will i wire this he just shrugs the shoulders and says im not the electrician.
Just because a plumber fits lots of motorised valves etc into an installation does not make it correct from his point of view.

Ill give you an example i had a house like in the op case, the plumber very inexperienced as was found out, he had 9 motorised valves and 4 pumps fitted along with various stats which he wanted to control various zones.
I took one look at the system and said straight out i wont wire that, not alone from all the unnecessary auxiliary equipment but because he had a pump fitted to the gravity hw circuit from the solid fuel along with other small issues. Wouldnt i be the nice boy wiring up such a case?

yes plumbers have an unfortunate habit of leaving electricIan's in the dark when it comes to heating systems and how they wish them to operate

2011

Sir Arthur Daley wrote: »

Having several motorised 2 or 3 way valves and pumps and stats and having them do what the plumber asks.

Assuming that he was prepared to put his requirements in writing and the customer agreed I can't see the problem. Ultimately the plumber has to take ownership of the heating system and the electrician shown ensure that the control requirements are met as specified by the plumber. If the electrician does this and the heating system fails to function correctly it is the plumber that will be held accountable.

Sir Arthur Daley

2011 wrote: »

Assuming that he was prepared to put his requirements in writing and the customer agreed I can't see the problem.

Would a solicitor be necessary present to construct and to have this writing legal binding?

2011

Sir Arthur Daley wrote: »

Would a solicitor be necessary present to construct and to have this writing legal binding?

That depends on your plumber

From my experience if a heating system does not work as it should the memory of different trades can become "confused".
All of a sudden you may find that the customer is told that if the electrician had just wired it as instructed the system would work fine.
By the time the issues with the heating system are detected it may be very expensive and difficult to make the changes that it is claimed are required.

However if you can show that the heating controls function as per the plumber’s instructions by referring to his written instruction that the customer has already approved you are in a far better position. Once heating controls get any way complicated it is not prudent to depend on peoples recollection of conversations that occurred several months ago.

The written description of the operation of heating controls does not have to be an elaborate complicated, document.
It should just be a few lines written in simple English.
You could simply email the customer & plumber with a description starting with “Following our earlier conversation my understanding is that you require the heating controls to function as follows…”. It can finish with “Once you confirm that my interpretation is correct I can then proceed. Please note: It may be costly and / or impossible to make changes at a later date if the job is too advanced”.

That way you are covered and everyone knows where they stand.
The days of verbal contracts and site instructions are long gone.

K.Flyer

If I am working on, for example, a house renovation with all trades on site, and I am doing a heating control system I will map out to the electrician what wiring I want and where and I will check to ensure that its done that way before its all plastered over.
At the end of the day the heating system is my responsibility, because I am the one who will get the call if it does not work.
I know its one of those cross over areas between our trades, but personally I feel if you are working on or installing a heating system you should at least know how it should be wired up, even if you prefer an electrician to do it for you.

2011

K.Flyer wrote: »

If I am working on, for example, a house renovation with all trades on site, and I am doing a heating control system I will map out to the electrician what wiring I want and where and I will check to ensure that its done that way before its all plastered over.

Obviously it is an advantage if the plumber knows how the heating controls should be wired, but this is not essential once the plumber knows how it should function.

Example of control description from plumber to electrician:

3 channel time clock is used to control the heating system:

Channel 1 operation:
This channel is for the downstairs radiators. When activated the downstairs zone valve should open if the downstairs stat reads a temperature that is below the set point on same.

Channel 2 operation:
This channel is for the upstairs radiators. When activated the upstairs zone valve should open if the upstairs stat reads a temperature that is below the set point on same.

Channel 3 operation:
This channel is for the domestic hot water (DHW). When activated the DHW zone valve should open if the hot water cylinder stat reads a temperature that is below the set point on same.

The boiler should only fire one or more of the zone valves are open.
Bring a permanent feed to the boiler for overrun.

___________________

To a competent electrician designing, wiring and testing from the above is not a difficult task.

At the end of the day the heating system is my responsibility, because I am the one who will get the call if it does not work.

Exactly my point.
If the plumber gives simple clear instructions like that to an electrician you should both know exactly where you stand.

salmocab

K.Flyer wrote: »

If I am working on, for example, a house renovation with all trades on site, and I am doing a heating control system I will map out to the electrician what wiring I want and where and I will check to ensure that its done that way before its all plastered over.
At the end of the day the heating system is my responsibility, because I am the one who will get the call if it does not work.
I know its one of those cross over areas between our trades, but personally I feel if you are working on or installing a heating system you should at least know how it should be wired up, even if you prefer an electrician to do it for you.

I must introduce you to the builders we work for

salmocab

2011 wrote: »

Obviously it is an advantage if the plumber knows how the heating controls should be wired, but this is not essential once the plumber knows how it should function.

Example of control description from plumber to electrician:

3 channel time clock is used to control the heating system:

Channel 1 operation:
This channel is for the downstairs radiators. When activated the downstairs zone valve should open if the downstairs stat reads a temperature that is below the set point on same.

Channel 2 operation:
This channel is for the upstairs radiators. When activated the upstairs zone valve should open if the upstairs stat reads a temperature that is below the set point on same.

Channel 3 operation:
This channel is for the domestic hot water (DHW). When activated the DHW zone valve should open if the hot water cylinder stat reads a temperature that is below the set point on same.

The boiler should only fire one or more of the zone valves are open.
Bring a permanent feed to the boiler for overrun.

___________________

To a competent electrician designing, wiring and testing from the above is not a difficult task.



Exactly my point.
If the plumber gives simple clear instructions like that to an electrician you should both know exactly where you stand.

In these types of setups sometimes its more where the MVs end up, had a plumber put the valve in a different location to where he said it was gonna be once i.e. was going to be beside the boiler but ended up beside the hot tank but never mentioned the change till I came back to finish the heating system.

2011

salmocab wrote: »

In these types of setups sometimes its more where the MVs end up

True.

How did it ever come about that two trades are needed to wire a domestic heating system

salmocab

gary71 wrote: »

How did it ever come about that two trades are needed to wire a domestic heating system

Well one does the one that hurts the other does the ones that either get you wet or catches fire. Each to their own

salmocab

salmocab wrote: »

Well one does the one that hurts the other does the ones that either get you wet or catches fire. Each to their own

Yea, but it's really easy to do both without the drama.

frankmul

Going back to the op setup, should there be a mV on the cylinder to prevent it overheating? What is the cylinder stat controlling?

And I'm not trolling, I was used to a environment where sparks rarely wire a domestic heating system, heating engineers do, so the added issues that i come across between the separate trades can be very interesting:D

salmocab

Yeah I know some plumbers that can do the wiring on fairly standard 3 zone systems but it seems that more and more the systems are getting more complicated with UF and various green type installations even occasional dual source systems like the OPs, which I think everyone has forgotten by the way, that have contactors. I think most plumbers especially when its a new build with a spark on site would prefer to leave it to the spark.