Central Heating controls

Sir Arthur Daley · 02-07-2014 4:51pm

mikeyjames9 wrote: »

.

i have worked on all types of heating systems sporadically

and i'm not aware of any regulation that says a fused spur beside the boiler must be the starting point of the heating installation

You must not be following the boilers manufacturing instructions if you dont think a fused outlet needs to be adjacent to the boiler and that this fused outlet also isolates the system auxillary wiring.

mikeyjames9 · 02-07-2014 5:39pm

Sir Arthur Daley wrote: »

You must not be following the boilers manufacturing instructions if you dont think a fused outlet needs to be adjacent to the boiler and that this fused outlet also isolates the system auxillary wiring.

are you referring to a specific boiler?

id be surprised if a boiler instruction manual states that the boiler isolator must also isolate the control circuit

I have worked on different systems occasionally with full sets of drawings and the boiler isolator only isolates the supply to the boiler

02-07-2014 5:42pm

gary71 wrote: »

Appliance specific and including external controls:

Resistance to earth:
Earth continuity test:
Short circuit
Mains voltage and polarity tests

The tests sound a bit strange.

Perhaps you can clarify:

1) Regarding the "resistance to earth test".
Resistance to earth between what two points?
Do you mean resistance to the general mass of earth from the boiler enclosure?
Or resistance beteen the CPC at the point of termination at boiler and the MET?
I am guessing that you wanted to say earth fault loop impedance test, is this correct?

2) Please explain what you mean by the "short circuit" test? What are you measuring, current, resistance or impedance? What is the purpose of this test?

3) In terms of the mains voltage test are you just checking that mains voltage is present (and polarity) or are you checking for volt drop as well?

mikeyjames9 · 02-07-2014 5:55pm

2011 wrote: »

The tests sound a bit strange.

Perhaps you can clarify:

1) Regarding the "resistance to earth test".
Resistance to earth between what two points?
Do you mean resistance to the general mass of earth from the boiler enclosure?
Or resistance beteen the CPC at the point of termination at boiler and the MET?
I am guessing that you wanted to say earth fault loop impedance test, is this correct?

2) Please explain what you mean by the "short circuit" test? What are you measuring, current, resistance or impedance? What is the purpose of this test?

3) In terms of the mains voltage test are you just checking that mains voltage is present (and polarity) or are you checking for volt drop as well?

I believe they are the same tests that appeared on a recent thread from another RGI

a shambles of a set of tests

a couple of them are hazardous to the welfare of the unsuspecting RGI with his multimeter

02-07-2014 6:00pm

2011 wrote: »

The tests sound a bit strange.

Perhaps you can clarify:

1) Regarding the "resistance to earth test".
Resistance to earth between what two points?
Do you mean resistance to the general mass of earth from the boiler enclosure?
Or resistance beteen the CPC at the point of termination at boiler and the MET?
I am guessing that you wanted to say earth fault loop impedance test, is this correct?

2) Please explain what you mean by the "short circuit" test? What are you measuring, current, resistance or impedance? What is the purpose of this test?

3) In terms of the mains voltage test are you just checking that mains voltage is present (and polarity) or are you checking for volt drop as well?

Copy and paste hence: http://boilerfaultfinder.com/electrical-safety-checks/240-v-test/

If I can get hold of more specific testing procedure I'll stick it up.

02-07-2014 6:18pm

gary71 wrote: »

Copy and paste hence: http://boilerfaultfinder.com/electrical-safety-checks/240-v-test/

If I can get hold of more specific testing procedure I'll stick it up.

I am not looking for a procedure.
My question was "I would be interested in knowing which of the above tests do RGIs are obliged carry out (if any)?"

The link you have provided shows a multimeter being used to read 240VAC, pretty menaingless and does not answer anything.

The tests you listed do not make sense, I assume that they were written by someone non-technical.

Can you list the electrical tests that RGIs are expected to carry out on heating controls?

Can you answer the questions listsed in my last post?
The tests you have listed do not make sense.

02-07-2014 7:15pm

gary71 wrote: »

I have been involved in domestic heating wiring all my working life I am happy the installs I did and any rewires were safe, I also worked for British Gas that employed thousands of gas engineers like myself so working in a environment where safety was paramount I am happy if not doing a IR test resulted in a issue my working practises would of changed over night.

It is not always about you and / or how things are done in the UK
I am not questioning your ability and in this country ET101:2008 applies.

What I am disagreeing with is your statement "I think only RGIs should be wiring heating systems".

My point is that RECs are expected to carry out certain electrical tests on all of the wiring that they install.
When RGIs install part the wiring for the heating controls they do not carry out an IR test according to you. When I asked what tests they carried out your reply was very confusing and so far you have not clarified.

When I asked "Which insulation tests do you think should be carried out in a domestic electrical installation and why?" you were unable to answer.

Now I know a bit more I would be happy to see IR testing of heating wiring as a given but at the moment the CER don't see a need for it and your own electricians don't do it very often( i'v never seen it done)

The fact that some electricians do not comply with the regulations is a disappointing fact, but also irrelevant. It is a bit like saying that "sure if everyone else drinks and drives then it is ok for me to". The aim should not be to install everything to the minimum standard that you can "get away with".

The other question that you have avoided is how you know that the integrity of the insulation on the cables you have installed has been maintained. Suggesting that it has been ok so far and that you have not seen any evidence to suggest that this is an important test does not wash. The ETCI (and IEE) see good reason to carry out IR tests on domestic installations.

If you're job was to follow up on heating installation issues you would understand why that comment was made, electricians in general don't take ownership of heating as it's not their cert

I can understand why this would be very frustrating.
I would be annoyed too.

The heating system in my home was installed very badly. Leaks everywhere, the system is constantly loosing pressure, the toilets don't flush properly, the rads are falling off the walls. I don't think that the solution is to get a good electrician to plumb my house! ....and yes I admit the heating controls were installed incorrectly by an electrician!!! In fact the wiring was appalling.

how does a sparks learn how heating controls interact if they don't understand heating

They should wire up the heating controls so that they function in the way that the RGI tells them it should.

a heating engineer learns from trial and error what works best and where to poisition it

A heating engineer according to the link you sent me is a very different animal from a RGI.

how many electricians understand they are putting lives at risk(depending on the boiler) by putting 230v on the auxiliary or bringing a switch live back to the boiler instead of using the 230v from the other side of the link in the boiler.

Not enough understand, I agree.
Unfortunatley there are cowboys out there.
That still does not justify getting RGIs to wire heating controls IMHO.

I could also ask:
How many bad plumbing jobs are there in the country?
How many DIYers have made dangerous electrical modifications?

I think by not understand heating control or the individual characteristics of boilers right now is a bigger issue due to the problems it causes than the very very RGIs not doing a IR test.

I agree.

I also think that there are some very poorly trained electricians out there and that training is required in this area. Cooperation is required between the trades.

Your understanding of plumbing and gas fitting has you at a disadvantage, it is well known and fairly evident that having a similar mindset allows plumbers(or electricians with grasping heating design) to grasp the principles of electrical testing or design quite quickly when the training incorporates already used testing procesdures

It would seem that my view is shared by our training authorities.
There is no short cut to becoming an electrician in Ireland.

Also are you aware that electricans don't even have good working practise for the most basic of electrical components, the switchable fused spur is always wired as the starting point of a installation and is sited within arms length of the appliance, the position and type of spur is dependant on each electrican and I give a big thumbs up to those electricians who go to the effort of doing it right, thank you.

I am more aware of the ability (or lack thereof) than you would think.
I have to walk down and sign off packages as part of my job.

Training, training and more training.

Yup!

Understanding gas boilers and their funkiness isn't rocket science, electricians have transferable skills and could be made to sit a competency paper to prove they understand what their wiring and how to get the most out of the installation.

As I am sure you know there is quite a bit to the electrical trade.
In my view it is impossible to do too many courses, the training should never finish.

Right now it isn't working and no one is interested in fixing it, what's the point of having all the gear if you have no idea, why does the idea of RGI doing wiring generate more posts than the level of wiring being done right now, the OPs wiring problems are not unique I'm sorry to say.

Right now the standard of pluming, carpentry and electrical is also very poor in many housing estates built during the Celtic Tiger.
This is not an issue that is unique to the electrical trade.
As you say more training is required as well as enforcement of the rules and consequences for those that choose to ignore them.

Sir Arthur Daley · 02-07-2014 7:27pm

mikeyjames9 wrote: »

are you referring to a specific boiler?

id be surprised if a boiler instruction manual states that the boiler isolator must also isolate the control circuit

Do you understand what you are saying? are you seriously suggesting the fuse outlet (spur) beside the boiler only isolates the main supply and that one has to locate another isolater else where to isolate the auxillary wiring into the boiler, remember the auxillary wiring may not be volt free, some use a relay within the pcb area to give the volt free connection(s) to the boiler.

I have worked on different systems occasionally with full sets of drawings and the boiler isolator only isolates the supply to the boiler

I have worked on systems where this has been the case too where big fancy drawings were produced too, does not mean it is not right and correct.

mikeyjames9 · 02-07-2014 8:49pm

Sir Arthur Daley wrote: »

Do you understand what you are saying? are you seriously suggesting the fuse outlet (spur) beside the boiler only isolates the main supply and that one has to locate another isolater else where to isolate the auxillary wiring into the boiler, remember the auxillary wiring may not be volt free, some use a relay within the pcb area to give the volt free connection(s) to the boiler.

I have worked on systems where this has been the case too where big fancy drawings were produced too, does not mean it is not right and correct.

hmm ok i've had a few beers but
let's see if you if you know what you are saying?

if the auxiliary wiring is a switched live the boiler can be isolated via a 4-pole isolator..many oil boilers are wired this way

correct?

also on the volt free issue

the volt frees(there may be more than one) may be wired in multicore from a heating controller to the boiler

I'm not aware of any requirement to switch off the heating controller at the boiler or even isolate the volt frees for that matter

it may be specific to gas boilers that supply a volt free but I don't think it's a general requirement

shane 007 · 02-07-2014 9:39pm

1st manufacturer's manual I looked up, Vokera, it states in capital letters
"ANY EXTERNAL CONTROL OR WIRING MUST BE SERVED FROM THE SAME ISOLATOR AS THAT OF THE APPLIANCE".

In IS813, it states Annexe K, K2.1.2,
"Gas appliances that require an electrical supply shall be connected via a double pole switched fused spur box or a suitable socket as indicated by the manufacturer."

Sir Arthur Daley · 02-07-2014 10:44pm

mikeyjames9 wrote: »

hmm ok i've had a few beers but
let's see if you if you know what you are saying?

if the auxiliary wiring is a switched live the boiler can be isolated via a 4-pole isolator..many oil boilers are wired this way

correct?

We are not talking about oil boilers.

I'm not aware of any requirement to switch off the heating controller at the boiler or even isolate the volt frees for that matter

Requirement for what?

shane 007 · 02-07-2014 10:54pm

Sir Arthur Daley wrote: »

We are not talking about oil boilers.

Oil boilers would be the same criteria. Only difference would be a 5amp fuse instead of a 3amp fuse & the switched live out is not fed from the boiler but a permanent live from spur.
Any frost stats should also have their feeds from the same spur.
Oh but the spur does not have to be within 1m of the boiler, but generally is the best place for it, due to being the obvious point of isolation for service persons.

Sir Arthur Daley · 02-07-2014 11:11pm

shane 007 wrote: »

Oil boilers would be the same criteria. Only difference would be a 5amp fuse instead of a 3amp fuse & the switched live out is not fed from the boiler but a permanent live from spur.
Any frost stats should also have their feeds from the same spur.
Oh but the spur does not have to be within 1m of the boiler, but generally is the best place for it, due to being the obvious point of isolation for service persons.

In alot of oil boiler setups the isolater at the boiler e.g garage model one would only isolate power into the boiler, the control e.g time clock, stats, mv etc can be potentially live once spur inside house is on.
I personally feel one isolater is all that should be allowed, this should be local to the boiler as in a gas situation. Obviously extra wiring would be needed in the example of a garage model setup. The way the gas with one isolater setup is the correct and safest way.

shane 007 · 02-07-2014 11:33pm

Sir Arthur Daley wrote: »

In alot of oil boiler setups the isolater at the boiler e.g garage model one would only isolate power into the boiler, the control e.g time clock, stats, mv etc can be potentially live once spur inside house is on.
I personally feel one isolater is all that should be allowed, this should be local to the boiler as in a gas situation. Obviously extra wiring would be needed in the example of a garage model setup. The way the gas with one isolater setup is the correct and safest way.

That's the way we do them. 2no isolators at the boiler, one for burner & other for pump. These both would be fed from the main isolator within the property.

You could have just one isolator serving burner & pump but it hadn't to run the pump on its own when we get system filling issues.

Sir Arthur Daley · 02-07-2014 11:38pm

shane 007 wrote: »

That's the way we do them. 2no isolators at the boiler, one for burner & other for pump. These both would be fed from the main isolator within the property.

Do you not think one isolater as in gas should be the way forward? i know there is nothing wrong with the 2 isolater set up.

shane 007 · 02-07-2014 11:45pm

Sir Arthur Daley wrote: »

Do you not think one isolater as in gas should be the way forward? i know there is nothing wrong with the 2 isolater set up.

For gas, definitely only 1 isolator should be installed, unless you require a separate isolator for say an UFH wiring centre or similar appliance that may require to be electrically isolated from the circuit while the rest of the system is required to be live.

The main isolator should kill the power to all other isolators though.

Sir Arthur Daley · 02-07-2014 11:57pm

shane 007 wrote: »

For gas, definitely only 1 isolator should be installed, unless you require a separate isolator for say an UFH wiring centre or similar appliance that may require to be electrically isolated from the circuit while the rest of the system is required to be live.

Say an 8 zone ufh for example?

shane 007 · 03-07-2014 12:05am

There could be many examples.
When commissioning, you may only want the water circuit on & rather than having to turn down every stat, each UH1 could be isolated via a spur.
They are also very useful for fault finding on controls. Being able to remove parts of a system can save a lot of time when trying to narrow down the culprit for a fault.
I would have no issue with that, but the main isolator at the boiler must kill the live & neutral to all electrical components of the system.

What I hate to see & frankly I find extremely dangerous is the MV's grey being fed from a separate circuit in the hot press.

Sir Arthur Daley · 03-07-2014 12:13am

shane 007 wrote: »

What I hate to see & frankly I find extremely dangerous is the MV's grey being fed from a separate circuit in the hot press.

This often happens where not enough cores are put in, could happen for lots of reasons. The end of the day its the person who energised that is wrong. Like in what you illustrated there what a very dangerous and potentially lethal situation that is.

shane 007 · 03-07-2014 12:28am

Sir Arthur Daley wrote: »

This often happens where not enough cores are put in, could happen for lots of reasons. The end of the day its the person who energised that is wrong. Like in what you illustrated there what a very dangerous and potentially lethal situation that is.

And then the circuit it is fed from happens to be the same circuit as the flamin' alarm, switch off at the consumer unit, nee naw nee naw nee naw......

Robbie.G · 03-07-2014 7:08am

Personally i put the main isolator where ever the MVs are.If they are in the hotpress I fit the spur there and then fit a 3 pole isolator (fan type) at the boiler that way whoever is working at system has local isolation at the points that's needed

shane 007 · 03-07-2014 7:28am

Robbie.G wrote: »

Personally i put the main isolator where ever the MVs are.If they are in the hotpress I fit the spur there and then fit a 3 pole isolator (fan type) at the boiler that way whoever is working at system has local isolation at the points that's needed

The isolator at the MV would also have to kill both lives & neutral though as if at a later date an unsuspecting person could assume that isolator will kill the permanent & the switched live and not bother switch off the main isolator at the boiler.
Whilst working on it, the boiler switches on from programmed time & the MV becomes live at the brown.

It could lead to assumptions from unsuspecting person, but if the isolator killed all lives & the neutral, I don't see an issue with it.

mikeyjames9 · 03-07-2014 11:42am

Sir Arthur Daley wrote: »

I personally feel one isolater is all that should be allowed, this should be local to the boiler as in a gas situation. Obviously extra wiring would be needed in the example of a garage model setup. The way the gas with one isolater setup is the correct and safest way.

you're talking nonsense again

shane 007 · 03-07-2014 12:42pm

mikeyjames9 wrote: »

you're talking nonsense again

Please elaborate as to why you think this nonsense, as this would be the correct method & specified/accepted by gas boiler manufacturers.

mikeyjames9 · 03-07-2014 12:57pm

shane 007 wrote: »

Please elaborate as to why you think this nonsense, as this would be the correct method & specified/accepted by gas boiler manufacturers.

only 1 isolator allowed?

there may be separate points of isolation needed

Mr daley keeps contradicting himself anyhow and changing his stories

mikeyjames9 · 03-07-2014 1:21pm

shane 007 wrote: »

Please elaborate as to why you think this nonsense, as this would be the correct method & specified/accepted by gas boiler manufacturers.

Rule No 555.1.2

Description: Local isolation required for motorised valves, oil burner, heating system, circulation pump, etc

it's one of reci's top 10 breaches of the wiring rules
voltimum.ie/articles/top-10-breaches-et101-national-rules-electrical-installations

presumably Mr Daly is one of the transgressors given his views on number of local isolators

03-07-2014 1:23pm

2011 wrote: »

The tests sound a bit strange.

Perhaps you can clarify:

1) Regarding the "resistance to earth test".
Resistance to earth between what two points?
Do you mean resistance to the general mass of earth from the boiler enclosure?
Or resistance beteen the CPC at the point of termination at boiler and the MET?
I am guessing that you wanted to say earth fault loop impedance test, is this correct?

I'll do my best but I don't know what the current training standard are and I don't teach RGIs .

No a EFLI is not done by RGIs but as RGI is not a trade qualification like NVQ or City and Guilds but a add on to a trade there maybe many who do RFLI and IR testing.

To do a resistance to earth test you first isolate the installation electrically then turn the multimeter to the highest resistance reading setting and test between live and earth, then repeat test between neutral and earth, you do this at the operating switches in the correct sequence of the circuit, starting at the spur including either side of the programmer.

Your looking for a reading of infinity or OL. Your looking to prove the integrity of the earth cable across the circuit.

2011 wrote: »

2) Please explain what you mean by the "short circuit" test? What are you measuring, current, resistance or impedance? What is the purpose of this test?

Using a multimeter set to its lowest resistance setting and with the installation electrical disconnected but all installation switches turned on(you may have to test either side of a programmer again) you then test between live and neutral looking for a circuit resistance of greater than 100ohms before the 3 amp fuse and a reading no less than 20 ohms after.

This is to prove the there is no short across the live and neutral of the heating circuit.

2011 wrote: »

3) In terms of the mains voltage test are you just checking that mains voltage is present (and polarity) or are you checking for volt drop as well?

Only:
Live to neutral 240v
Live to earth 240v
Natural to earth 0-15v

Earth continuity:
Electrically isolate the circuit then with the multi meter set to its lowest setting and starting from the spur, test between the earth and other circuit earths leading up to the appliance, then test the earth points on the major components, case, pipework etc.. within the appliance, looking for a reading less than 1 ohm

RGIs are also expected to have a safe electrical isolation procedure.

mikeyjames9 · 03-07-2014 1:29pm

those tests are not proper electrical tests

they are DIY multimeter tests

one or two of them are hazardous to the RGI carrying out the tests

03-07-2014 1:40pm

mikeyjames9 wrote: »

Rule No 555.1.2

Description: Local isolation required for motorised valves, oil burner, heating system, circulation pump, etc

it's one of reci's top 10 breaches of the wiring rules
voltimum.ie/articles/top-10-breaches-et101-national-rules-electrical-installations

presumably Mr Daly is one of the transgressors given his views on number of local isolators

Gas heating comes under gas regs cert and there's a different approach.

Do you understand the added risks to those working on a domestic gas installation when the main boiler isolation isn't the system isolation or can you understand the benefit of finding the circuit isolation in one place for every job you do.

A few years a go I was in a loft where the sparks wired the boiler into a plug socket with out a switch so I pulled out the plug unfortunately there was still power to the boiler as there was a seperate isolation for the circuit and while hold the plug a got a shock that lasted a long time as I made a fist around the plug so I just stood there and fried.

Why when I look to isolate a appliance or work on a m/v do I have to play this game ye invented of hide the spur?

mikeyjames9 · 03-07-2014 1:47pm

local isolation of mv's is covered by et101

your installation won't pass inspection regardless of what you believe about 1 heating system isolator beside boiler

Central Heating controls

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