Immersion hot water system, what schedule is most optimal?

Rodders53

Switch off both immersion heaters at their mains isolators (even at the consumer unit if you can't find them in the HW cylinder cupboard area).  Immersion heaters are for emergency-only use when the gas boiler breaks down.

On gas that HW tank will likely take around 30-60 minutes to reheat a tankful of water.   So set the HW timer for around an hour before you need the HW for showers AM and again later in the day for the evening ones.  No need for any long times on (unless the HW doesn't get hot enough for your family use).
But you need to find the controller-timer for setting that.  

CH temp (and maybe times) will be via the WR1 British Gas receiver (probably).

I'm not a big fan of these smart heating controls as the simple timers can work extremely well and are cheaper (especially when already there = zero cost).

Apodemus

Section62 said:

Apodemus said:

That bottom pic looks like a motorised valve on a loop from the central heating?

With the central heating on, move the lever on the silver box across and see if the pipe warms up.

The manufacturers generally instruct that the manual lever shouldn't be used when the electrical supply to the system is turned on - there is risk of damage to the valve.

s62, I'm sure you are correct and the manufacturers don't want people playing with the motorised valves, although I doubt if a one-off manual attempt is going to cause much harm. 

It is quite possible that the valve or the motor has already failed and is in "shut" mode and  it seems to me that the simplest first step for Arfa.... is to rule that out and find out if the system will indeed manage to heat the hot water.  I guess the correct way would be to pull the lever across, locking it in place, then turn on the heating to see if the pipe warms up.  It is possible that the lever won't move across at all, indicating that the valve is stuck and probably needs to be replaced, but if it does move and the pipe heats up, then Arfa knows that he needs to spend further time investigating the controls.

Bendy_House

I can't see any issues with doing this with a 'zone' - 2-port - valve like these, and I've done this repeatedly myself.

These valves are either powered 'on' or not. So, manually opening them up - when it's powered 'off' - shouldn't cause any issues.

3-port 'diverter' (soz, couldn't resist...) valves, on the other hand, can also be electrically suspended in its mid position, so manually acting against this could very well cause it a headache.

I think.

Arfa__

Ok, some more, better photos. So i didn't realise the boiler was heating the tank and there is this two-way value. I see the switch underneath on it now. There's a mains switch labelled 'water heater' in the airing cupboard next to the tank. Currently on, but not lit red. I assume this cuts off the immersion heaters? And I should turn this off until an emergency and the boiler is out of action?

The boiler in the garage and control stuff next to it.

Upstairs in the airing cupboard is the tank:

Control wise, there's a Hive relay (?) in the utility room close to boiler and a Hive control panel in the hall:

Arfa__

Regarding the two-value:

With hot water off on the Hive control panel, it remains in the 'unlocked' position (to the left as you look at the photo of the lever above) and when I tried to move it, it resisted and moved itself back.

With the hot ware on, I was able to move the lever freely to the locked position (to the right as you look at the photo above).

The 'hot water' light on the Hive relay and boiler kicked in and I could feel the water pipe getting hot on either side of that valve.

When I then turned the hot water off, the valve motor moved the lever back to unlocked position (to the left).

Does this behaviour sound right?

That WR1 controller, has a red light next to the 'receive/alarm' label - is that OK?

What is the Potterton device that is set to 5C? Freeze protect fail safe kick in?

So, have I just been completely mistaken in assuming our hot water was from electric?! (what a muppet am I?)

And does that mean the hot water temp is actually controlled by the dial on the boiler itself?

Thanks again for all the input, I've not had a system as complex as this before, last place was just a simple Combi boiler...

Bendy_House

Arfa__ said:

Regarding the two-port valve:

With hot water off on the Hive control panel, it remains in the 'unlocked' position (to the left as you look at the photo of the lever above) and when I tried to move it, it resisted and moved itself back. Yes, it returns whenever it's released or turned off under spring pressure. That's fine.

With the hot water on, I was able to move the lever freely to the locked position (to the right as you look at the photo above).

The 'hot water' light on the Hive relay and boiler kicked in and I could feel the water pipe getting hot on either side of that valve.

When I then turned the hot water off, the valve motor moved the lever back to unlocked position (to the left). Perfect. When you turned on the hot water, the first thing that happens is that valve 'whirrrrs' open (lever goes floppy, since the valve has moved to the other side), and the boiler and pump fire up. Since the valve is open, you'll feel the pipe getting hot as the boiler water starts to flow into the cylinder to heat it up (via a heating coil of pipe).

Does this behaviour sound right? Yup.

That WR1 controller, has a red light next to the 'receive/alarm' label - is that OK? No idea. Can't see what that receiver is still doing there, as I'd have though the newer Hive receiver would be doing all the work. I wonder if it has to do with the frost stat, or that other pipe stat? I'll need to look it up...

What is the Potterton device that is set to 5C? Freeze protect fail safe kick in? Yes, especially since the boiler is in the garage.

So, have I just been completely mistaken in assuming our hot water was from electric?! (what a muppet am I?) Yup - a complete muppet :-) (Oops - perhaps not! 7 pics up from t'bottom, you can see a square grey box on the side of the cylinder, near the bottom. Yes? That's is very likely to be the electric immersion heater, which should really be used as a back-up, or if you get cheap rate leccy overnight, or if you have solar panels. That should have a switch somwhere. Eek - is that it on the opposite wall on the right? If so, it looks 'on'. BUT, the red light isn't lit? Perhaps the fuse is blown? Or it's on a timer? Do you have Economy 7 leccy or anything?

And does that mean the hot water temp is actually controlled by the dial on the boiler itself? Maybe, but it shouldn't be. The cylinder should also have a 'stat attached to its side, and that will have a temp dial on it. When the boiler has heated the tank to that temp, it should tell the boiler to turn off. I don't see that 'stat. I wonder what that smaller grey box it further up? It doesn't have a cable going to it though... Confused.

Thanks again for all the input, I've not had a system as complex as this before, last place was just a simple Combi boiler...

You have a modern Hive controller, so that's good. Do you know how to use it? Set it? Programme it? Override it? Is there a 'Hub' fitted to connect to the interweb? If so, you'll find it MUCH easier to control via a phone or PC App - really, MUCH better.

Bendy_House

Ooookkay.

YELLOW: is a pipe stat. This detects the temp of that RETURN pipe. No idea why it's there, but perhaps it's an 'overrun' stat, so it keeps the pump running after the boiler has gone off, until all the boiler's heated water is cooled down. Don't worry about it.

ORANGE: is a magnetic filter. That's good - it should catch any sludge flying about your system. Worth learning how to clean it out, unless you have annual services, in which case ask your plumber to do it!

RED: That's your circulating PUMP. Don't worry about it.

BLUE: That's your old WR1 receiver. No idea what that's doing there. Will try and find out...

GREEN: Most likely your mains boiler supply on/off switch. If you turn this off, then EVERYTHING to do with your boiler - controls, receivers, etc - should turn off. Should.

PURPLE: That's your wiring centre - all the wires go in there. You do not want to have a peep... So, don't worry about it.

BROWN: That's your frost stat. If the temp in there drops to below 5oC, it'll turn the boiler on to keep it warm.

Apodemus

Arfa__ said:

Regarding the two-value:

With hot water off on the Hive control panel, it remains in the 'unlocked' position (to the left as you look at the photo of the lever above) and when I tried to move it, it resisted and moved itself back.

With the hot ware on, I was able to move the lever freely to the locked position (to the right as you look at the photo above).

The 'hot water' light on the Hive relay and boiler kicked in and I could feel the water pipe getting hot on either side of that valve.

When I then turned the hot water off, the valve motor moved the lever back to unlocked position (to the left).

Does this behaviour sound right?

I think we are getting somewhere!  Time to pause and review the evidence.

You have unexpectedly high energy usage.  You have a hot water system controlled by a motorised valve that switches off properly, but doesn't seem to switch on when instructed to do so (but can be opened manually).

Occam's razor might suggest that these two pieces of information point to the immersion being on, the water in the cylinder being hot and the tank thermostat giving a message that the motorised valve should remain shut.

So first job is to hunt down the switch that controls the two immersion heaters in the tank.  Once these are off, and with the hot water in the tank used up, then see if the Hive controls will send a message to the motorised valve to open it. 

If you can't find a switch for the immersion heaters, then look at your fuse board/consumer unit as it is most likely that the immersion heaters will be on a separate fuse.  If you know what you are doing, you could make sure that the immersions are off, by switching off at the fuse box.  (It's also not unheard of for the immersion switch to be adjacent to the consumer unit, but I'd be surprised if this was the case on a modern system like yours). 

Le_Kirk

Bendy_House said:

Ooookkay.

YELLOW: is a pipe stat. This detects the temp of that RETURN pipe. No idea why it's there, but perhaps it's an 'overrun' stat, so it keeps the pump running after the boiler has gone off, until all the boiler's heated water is cooled down. Don't worry about it.

ORANGE: is a magnetic filter. That's good - it should catch any sludge flying about your system. Worth learning how to clean it out, unless you have annual services, in which case ask your plumber to do it!

RED: That's your circulating PUMP. Don't worry about it.

BLUE: That's your old WR1 receiver. No idea what that's doing there. Will try and find out...

GREEN: Most likely your mains boiler supply on/off switch. If you turn this off, then EVERYTHING to do with your boiler - controls, receivers, etc - should turn off. Should.

PURPLE: That's your wiring centre - all the wires go in there. You do not want to have a peep... So, don't worry about it.

BROWN: That's your frost stat. If the temp in there drops to below 5oC, it'll turn the boiler on to keep it warm.

The pipe stat would (probably) be used in conjunction with the frost stat.  The frost stat says (to use Bendy phrases) "Oooh, I'm cold, turn on the boiler" and the pipe stat says "OK, I've warmed up nicely, you can turn off the boiler".  I thought over-run stats and overheat stats would be internal to the boiler.

Bendy_House

Le_Kirk said:

Bendy_House said:

Ooookkay.

YELLOW: is a pipe stat. This detects the temp of that RETURN pipe. No idea why it's there, but perhaps it's an 'overrun' stat, so it keeps the pump running after the boiler has gone off, until all the boiler's heated water is cooled down. Don't worry about it.

ORANGE: is a magnetic filter. That's good - it should catch any sludge flying about your system. Worth learning how to clean it out, unless you have annual services, in which case ask your plumber to do it!

RED: That's your circulating PUMP. Don't worry about it.

BLUE: That's your old WR1 receiver. No idea what that's doing there. Will try and find out...

GREEN: Most likely your mains boiler supply on/off switch. If you turn this off, then EVERYTHING to do with your boiler - controls, receivers, etc - should turn off. Should.

PURPLE: That's your wiring centre - all the wires go in there. You do not want to have a peep... So, don't worry about it.

BROWN: That's your frost stat. If the temp in there drops to below 5oC, it'll turn the boiler on to keep it warm.

The pipe stat would (probably) be used in conjunction with the frost stat.  The frost stat says (to use Bendy phrases) "Oooh, I'm cold, turn on the boiler" and the pipe stat says "OK, I've warmed up nicely, you can turn off the boiler".  I thought over-run stats and overheat stats would be internal to the boiler.

Thanks... I think...

I'd have thought the overrun would be integral too, but just can't think of any other purpose for that pipe stat.