A delight to see a clearly structured presentation without ghastly distracting music and wobbly pictures. Thank you so much John. I know how much work these are to do.
Thanks John I'm apprentice plumber and I'm trying to get my head around the wiring and I'm learning from you instead of my lectures as they are crap. You make things and explain things in a good way.thank you
Thank you john, I'm apprentice plumber I've been onsite with engineer for newly 1 year but I learn more from you. This is really helpful. God Bless you.
Thanks John, I've been watching your videos this weekend and they are very well presented & helpful. Sorry to be pedantic, but at 19:43 I have found, in my experience as a heating engineer, that the most common arrangement is Off, Off, On, On, rather than the other way round i.e. HW Off, CH Off, HW On, CH On
Thankyou for taking the time to make this video. The advice about the fan continuing to run to help disperse heat answered our wiring dilemma and saved the time & expense of calling out an engineer. 🙂
One of the best, if not the best video explations on electrical layouts and regsI've seen, well presented and good clear accurate information, a pleasure to watch,,,,,, keep up the good work, well done, could you do some tutorials on relays, contractors, recycles etc,,, just a suggestion.
Thanks for the very interesting videos. Just for interest:- My system has a gas boiler, a pump and a programmer but only one valve to shut off the heating if not required, giving priority to water by gravity. Hope that makes sense to you. The valve opens when heating switches on. The whole system was installed by a friend in 23 hours(working) and we have a 4 bedroom house, he done it this way to keep the price down, I bought all the parts and he installed it, he charged us £80 labour so you can guess how many years ago that was. I've only had to replace the programmer, a Randall 3060 I think it was, with a Honeywell programmer which we still have and the boiler, everything else is still going. I've also still got a few lengths of 3/4" piping, it's amazing how thick the wall of the pipe is compared to todays standards. Thanks again and I've subscribed so will be popping back now and then.
Hello John. Thank you for a very interesting video.I’m especially interested in the part with the wireless thermostat and receiver box on the wall near the boiler.I have just bought the nest system and I’m sure I can fit it all myself except I am confused with one particular wire. How do I know which wire is the “call for heat wire” and how do I locate it?
Hi John can you run a video on electrical connection and equipment required for domestic/commercial solar ( photovoltaic system) and explain how dc and ac converts in this system. Thanks
Excellent videos and information - thank you. I now know what all those wires and boxes do! A question - I'm considering installing a Nest Thermostat (third generation) and wondered if you could post a wiring diagram for the Nest system. Would also be useful to then see which components (and wiring) of the existing system effectively become redundant as a result (Eg the programmer and the wiring to/from?)
I would estimate that about between 2/3rd and 3/4 of fully pumped systems are Y-plan (1x 3 port valve) and the majority of the rest are S-plan (2x 2 port valves) there are some obscure ones like C-plan with 1x 2 port but the majority are quite simple. It’s surprising how many electricians don’t know how to wire heating systems even though it’s just motors and switches in principal
Most boilers these days actually have (besides the permanent supply) an LS, NS and LR connection. LS and NS supply the control system while LR is the switched live which fires up the boiler.
Hi JW, I love your videos. They are a great learning tool for me, but correct me if I'm wrong but doesn't your explanation of the programmer output terminals for 'HW ON' and 'CH ON' in this video contradict the explanation of the tutorial in your S Plan video? (Part 2)
There are still new boilers that only require a switched live, they only require a permanent live if they require a pump over run to circulate residual heat from the heat exchanger and all new pumps now must be “smart” pumps that modulate their output depending on the load on the system
hi John , what cable should I be using wiring this system up , I am used to using 2 core twin and earth , but when I look at 3core and earth they are all new colours , not brown , blue and earth ???
John.. please.. on my heating/water control panel, Drayton lp522 .. is the yellow light meant to stay on all the time.. Is it wired properly and can I turn it off from inside the panel..
The yellow light for the central display stays on all the time. The small red indicators either side should go on/off to show whether the heating and hot water is on/off.
I have a very old "boulter camray 5 oil fired boiler" and recently when I had to replace the programmer I found it only has a pump on the central heating side and nothing on the hot water side. When the hot water comes on it just turns on the boiler. When the heating comes on, only the pump turns on, meaning that you have to have the hot water on at the same time to heat the water.
I have a question which I can't find the answer to on Google and am hoping you might be able to help. When I was cleaning the other day, I accidentally went a bit too close to the central heating control panel and I think the smallest amount of water from the sponge must've leaked its way down inside. The control panel started to flicker and slightly buzz. I grabbed a wooden spoon and switched it off as quickly as I could. I haven't put it back on yet. Wondering if it would be safe to switch back on or even put the heating on or should I leave for perhaps longer? Have tried searching on Google but cannot seem to find an answer anywhere. Would really appreciate any advice. Thanks so much.
If it has dried out it may still work, but if enough water got in to cause it to malfunction, there is a very good chance it has been damaged permanently.
Strange that you use low voltage (240Vac), control there still, we have been using PELV here for as long as i can remember, a suitably sized 24volt transformer in the boiler powers everything else (except the pumps), those are controlled by 24vac relays. There should be an over temperature cutout (manually reset safety), in the boiler too. Great video just the same, you might catch up with us convicts one day :)
Hi John, is it really true that if you turn off unused radiators its saves gas? Because our thermostat is in one room so therefore how can turning other radiators make a difference?
+ChompChompNomNom The only way turning off unused radiators saves any real money is if the unheated rooms are well insulated from the rest of the house, and the doors to those rooms are permanently closed. As this is never the case, not heating one or more rooms just means the heat losses from the other rooms are much greater, as the heat moves from the heated rooms to the unheated ones through the uninsulated walls / floor / ceiling.
Excellent tutorial.. On an S plan, when another heating zone is required with a second motor valve and second room stat, I'm guessing you use a spare terminal in the wiring centre and take the s/l from the second stat to energise the second valve input (orange) with the output going to terminal 10 as usual to fire the boiler?
Hi - we have switched the electricity off in our house as we are going away. The boiler will obviously also be switched off. Is it a problem/is it dangerous?
Hi jw just a quick question I have a combi boiler with the standard programmer and I'm thinking of installing the hive thermostat dual chanel the question is will the hive replace the programmer or run alongside it like my existing thermostat does and maybe you could make a Video regarding these thanks Adam
Hive replaces both the programmer and thermostat, the one device does everything. A combi boiler is one which heats water on demand, there is no hot water cylinder, those need a single channel hive. If you have a hot water cylinder, a dual channel hive is required.
John Ward cheers john it's just a boiler and there's a tank upstairs ..as for the existing thermostat would it be removed and the live and call be joined and a blanking plate be put over it or would that be done at the boiler and then the wires at the thermostat be made redundant. Thanks for the reply
That's it - you will need to dual channel one. The Hive has a standard backplate, so may just fit onto the existing programmer plate without any wiring changes. Thermostat wires either connected together at the thermostat position, or put a link in the wiring box and remove the thermostat wires completely. If you do need to remove any wires, mark them all first and take several photos of all of the wiring so you know where they were connected - colour codes and terminal numbers can be different depending on who installed it originally.
Nice heating explantion! I do not get it why the valves are built this way in GB? Wouldn't it seem rather inefficient to have the valve always powered while open(which is most of the time)? Why even have a valve at all?? In most cases just a pump would just suffice! In Austria where I live mixing valves are used sometimes which use an actuator(motor). Also gas and oil are so last Century! Heat pumps are the way to go!
It would, but the connection for an electric boiler would be a separate circuit just for the boiler. These videos are about the control wiring, not the means of heating, which is usually gas or oil.
Hi John. I'm afraid you've got the connections to the cylinder coil the wrong way round. Edit: Now I've watched the whole video, there may not be an earth connection to a valve motor head if it's isolated from the valve body. I've got a pair of Sunvic valves here with plastic-bodied motor heads and just Live, Open, SwL plus Neutral - no earth.
+Graham Langley Easier to draw that way, avoids the flow/return crossing over. Sunvic valves are generally evil, they also make those which have motor on / motor off an no spring. A good idea but poorly implemented, they don't last long before some failure occurs.
+John Ward Their MoMo ones are exactly the ones I have, chosen because I wanted to be able to mimic way the old Switchmaster 3-port valve worked. The mechanics seem OK, the cct is OK with the 24V zener across the relay and the current-limiting resistor put back in, but the PCB design is terrible with too small clearances for mains voltages. I'm tempted to layout a new one instead of just replacing the worst track with a wire link. Edit: But it's no where near as bad as their Select 207xl programmer. I fixed a neighbour's one that failed on New Years Eve a few years back. How they could sell such a badly designed and produced bit of kit is beyond me. Swapped it for a Siemens RBW9 a few days later, discovering in the process that 'universal' backplates aren't.
+Graham Langley Perhaps I should add that the Sunvic MoMo valves won't emulate the Switchmaster, which stays in the last position and only moves when the demand changes, on their own. They need a home-brew controller, which can also give hot water priority.
Using mains voltages at the thermostats seems unusual. There must be a historical reason for this. Here in North America, the majority of heating, ventilation, and cooling systems (HVAC) use a low voltage such as 24 volts AC to power AC switches back in the central heating unit.
+Steve Rodgers Used not to be the case. My parents first CH boiler (gas) installed in '68 used 24Vac for the roomstat. I can't remember what the cylinder 'stat used.
in the UK we don't have "HVAC", we have "central heating" that is solely concerned with warming the place up. Really old systems have no electronics to control any of this, I've lived in a house where the boiler timer was a mains powered mechanical clock timer and the thermostat a simple bimetallic strip. So switching mains voltage makes sense.
In today's Green and Eco conscious environment are people becoming reluctant to have oil and gas boilers for heating and switching to Air Conditioning systems instead, or would that be price prohibited with the cost of electricity..?
+RedDragonUKTech Combi boilers are single outlet devices. Useless in a property with 2 or more bathrooms. They are frequently installed because they are cheaper and quicker to fit than a proper hot water system, rather than because they are actually suitable. There is also a myth about them being more efficient as they only heat what you use, but this is nonsense as most of the heat losses are from the pipework between the boiler/hot cylinder and the outlets.
+John Ward We have a half sized electric heater tank that feeds two bathrooms from one standard sized pipe. The pressure drops when you turn both sinks on hot. We had a problem with rusty water coming from the kitchen sink once. The plumber found the cause to be a bad anode in another miniature heater tank that was inside the wall under the countertop near the sink. @_@ That plumber will have nightmares.