Vaillant ashp (my battle with).

[zoothorn]

Could someone tell me:

 

I have the HW temp set to 46*C. Does this temperature have any bearing on the temperature the rads emit?

 

Thx Zoot

[Dillsue]

7 hours ago, zoothorn said:

I have the HW temp set to 46*C. Does this temperature have any bearing on the temperature the rads emit?

Yes it does...the hotter a radiator is the more heat it gives off.

 

The hotter you run the water leaving the heat pump the less efficient it becomes so it uses more electricity and costs you more to run. The solution to this problem is to run the heat pump cooler and have bigger radiators.

[Dillsue]

8 hours ago, zoothorn said:

I have the HW temp set to 46*C. Does this temperature have any bearing on the temperature the rads emit?

Just reread what you asked and realised that you're talking about the HW temp in your HW tank?? In that case the answer is no. The heat pump runs at different temperatures when it's heating the HW tank and when it's heating the radiators. The change in temperature is done automatically but you can set the time and temperature for both the HW and central heating.

[Nickfromwales]

12 hours ago, zoothorn said:

I don't think any installer would be -that- inept

Drumroll, please......

 

12 hours ago, zoothorn said:

It's where it was, in the small bedroom on a wall outside the cylinder enclosure (this thin wall is never ever, even barely warm).

Sadly, he is both inept, and lazy. This is completely unacceptable, barely a minimum (dogshit) level of give-a-feck.

 

The stat should absolutely NOT be in a bedroom with the airing cupboard and hot water cylinder, even more so if it's the box bedroom. That's lazy and totally against what the MI's would say "install the unit away from a source of heat or cool, and out of direct sunlight or draughts" is what instructions come with just about every room thermostat I've ever fitted.

 

12 hours ago, zoothorn said:

Only way I can move the thermostat is buying 30m of cable & running it thru an attic, drill hole in ceiling, run cable down to kitchen/ thermostat there.

I shall repeat myself, do NOT put the thermostat in the kitchen!!! 

 

12 hours ago, zoothorn said:

I don't think this is a sensible place to put it myself, as surely just --too-- cold??

Yes! And too warm when you're cooking, and for the hour after cooking, where the heating will then stay off thinking the house is warm enough.

 

12 hours ago, zoothorn said:

I'm never going to understand the basics of the difference between this ON setting that I thought was being suggested, & this timer setting that I thought wasn't being suggested. 

ON, would be the set temp (say 20^oC)..... with your heating running all day, all night, all year, with zero change and never stopping (until you told it to).

 

Look at "ON" as you getting into your car and driving around an empty M25 in the middle lane at 70mph, setting the cruise control to 70mph, and then never touching the throttle or the brake ever again; around and around you go at the same speed.

 

That is "ON".This is an example only, so no need to reply and say you'd never set it to do this, as I already get that .

 

So we won't be referring to "ON" in this thread. That ship has sailed, and we never need to discuss the "ON" setting ever again. 🤐.

 

Now for AUTO/TIMED.

 

Back to the driving analogy, so this would now be you slowing down for a 50mph speed limit (your heating at setback temp) or you speeding back up to 70mph when there an open road again (your heating running at comfort temp). No stopping or starting, just changing speeds between 50mph and 70mph, continuously, through the winter.

 

So if you convert speed of driving into warmth then this is how the AUTO/TIMED function works eg giving you cooler temps at night and warmer temp during comfort hours.

 

These are defined by you, as per the choices you dial into the heating schedule on the controller (as per my post with these times and temps, given as an example of where to start your trial run of setting the heating up properly for the very first time ever). If unhappy, you then work out why and then adjust the programmer.

 

12 hours ago, zoothorn said:

So what I don't want, is the heating on overnight. I don't want the heat, the wasted cost,

This is what the setback temp is for, and you simply set this low enough for the house to not get stone cold overnight. It won't 'heat' or 'overheat' you at night, and as you like a cool/cold bedroom you could even simply turn just that one rad off permanently, eg if you don't want to wake up to a warm bedroom, but don't want to wake up to a cold house.

 

The rest of the house would then not become ridiculously cold overnight, and would quickly recover to the comfort temp when told to do so (eg at 07:00 or 08:00, or whatever time is 1 hour before you get up each day).

 

Turning the heating "OFF" 100% overnight vs using a setback temp will cost more, as many folk on here have tried to explain. This is like asking your car to forever drive up a steep hill, and turning back again before getting to the wonderfully economical bit of flat road at the top of it, and consuming far more fuel doing this every 24hrs.

 

12 hours ago, zoothorn said:

(absolutely fumdamental is no machinery "wakes up" kicking into gear at 3am, no murmerings/ nothing/ not even outside cos some noise transmits via pipes, into bedrooms, the very rooms you least want mechanical noise entering at 3am).

As said, if that's an issue then turn your bedroom radiator off. You say you sleep with the bedroom window open in winter, whilst using an electric blanket(!), so zero point in using your bedroom radiator anyways.

 

Human beings are usually in deep sleep at 03:00, so you'd be unaffected by the rest of the heating system ticking over in the background, providing the setback temp to all of the other rooms (to prevent the stone cold house issue).

 

12 hours ago, zoothorn said:

Anyway point is I can't afford to buy new wireless thermostat/ transmitter- receivers. Nor can I afford a plumber to reposition this vrc700

Respectfully, I think you can, just you wont.

 

For context, you mention that adding new concrete floors may be an option, and that you are going to look into buying and installing a solar PV array, so <£100 to buy a stat like mine and the same for an installer to fit it shouldn't be any issue for you at all. If you haven't got £200 to your name then you best sell up and move into an economical 1 bed flat.

 

If you ask Octopus they will immediately refund the £300 that you are in credit, funds you obviously don't need, and then that gives you the money to buy and install the new stat (and will leave you some change).

 

12 hours ago, zoothorn said:

furthermore I'm lost immediately on the most seemingly simple stuff. Basic settings. 

 

Which is why I suggested fitting a stat like mine, as above, which is no more difficult to program than a Casio wristwatch or digital alarm clock.

 

 

Life is as hard as you make it, and it seems you are insisting on making it painfully hard for yourself.

 

Listen, change, improve, move on. I'm completely out of momentum here now, so if you're unwilling to take advantage of the enormous amount of time, effort, and energy that everyone has used up here then I have zero idea about how you can (or if you will) make any improvements.

 

That's not me being a dick btw, just that we've now delivered you at the crossroads and you now need to choose a direction. Time for action.

[-rick-]

1 hour ago, Nickfromwales said:

Turning the heating "OFF" 100% overnight vs using a setback temp will cost more, as many folk on here have tried to explain. This is like asking your car to forever drive up a steep hill, and turning back again before getting to the wonderfully economical bit of flat road at the top of it, and consuming far more fuel doing this every 24hrs.

 

Yes. Another way I've seen this explained is which of the following is the more efficient way to drive 100 miles:

 

1. Drive at 70mph constantly (maybe occasionally slowing down a little for traffic but basically staying at 70)

 

2. Everytime you see a gap in traffic you floor it accelerate as fast as possible until you hit traffic then you stop the car, wait for another gap to open up then floor it again.

[Nickfromwales]

5 minutes ago, -rick- said:

Everytime you see a gap in traffic you floor it accelerate as fast as possible until you hit traffic then you stop the car, wait for another gap to open up then floor it again.

I drive an 5.5L AMG, so is this not how I should be driving then?  I thought that was what everyone was referring to when they said make the most of stop/start driving  🚗💨

 

Great fun for winding up the Tesla drivers who hog the fast lane at 70.5mph, you know, the ones that pull out in front of you to then spend ~17 mins to overtake the car in the middle lane doing 70. You know who you are people......ffs!!!!!!!!!!!!!

[-rick-]

1 minute ago, Nickfromwales said:

I drive an 5.5L AMG, so is this not how I should be driving then?  I thought that was what everyone was referring to when they said make the most of stop/start driving  🚗💨

 

Haha, wondered if you'd say something like this.

 

You can have fun or efficient not both

[Nickfromwales]

4 minutes ago, -rick- said:

You can have fun or efficient not both

"Smiles per gallon" 

[marshian]

55 minutes ago, -rick- said:

 

Haha, wondered if you'd say something like this.

 

You can have fun or efficient not both

 

You can have both when it's not dragging round 2,000 plus kgs

 

 

 

I was fixing headlights so bumper had to come off

 

Edited 2 hours ago by marshian
Explaination of why it's in bits

[Nickfromwales]

3 minutes ago, marshian said:

I was fixing headlights so bumper had to come off

We digress, but that's my next job as the loom in the headlight of the GLS has dropped a core, canbus going nuts every now and then. ffs.

[sharpener]

On 23/02/2026 at 20:37, -rick- said:

 

Firstly, using the timer is not wrong as such, it comes down to HOW you use it. In your particular building, using the timer to stop the heatpump working for long periods is the issue. It's ok to use the timer to set a modest setback, ie, 2C. So most of the time you run at say 18C but overnight set it to 16C. But using the timer to say you want 20C for 2 hours and then 10C for the rest of the time just won't deliver the result you expect. This partly due to the way the heatpump works and partly due to your building.

 

 

I would guess that most people with heatpumps do use the timer. I can't tell you how to do it but it will be possible through the menus. You want to have a setback to setting the timer makes sense.

 

In my mind, first step is to get your warmer, second step is to optimise things so your system works in the most efficient and comfortable way for you. First step can be done by just setting to ON*, second step might need the timer to do but in a way theres no point learning to use the timer if you can't get warmer with the thing just set to ON.

 

* I do think the thermostat needs sorting first.

 

 

 

14 hours ago, zoothorn said:

I'm never going to understand the basics of the difference between this ON setting that I thought was being suggested, & this timer setting that I thought wasn't being suggested. 
 

I've tried today to read BB's link he sent me, but it's for the black controller vrc720, furthermore I'm lost immediately on the most seemingly simple stuff. Basic settings. 

 

I think the only way forward, is saying maybe what I don't want. And seeing if something fits around this. So what I don't want, is the heating on overnight. I don't want the heat, the wasted cost, nor any mechanical noise (absolutely fumdamental is no machinery "wakes up" kicking into gear at 3am, no murmerings/ nothing/ not even outside cos some noise transmits via pipes, into bedrooms, the very rooms you least want mechanical noise entering at 3am).
 

Thanks, Zoot

 

 

 

OK, here is the instruction manual for your VRC700 https://elearning.vaillant.com/vrc700/ci/en/documents/uk/infopool/Operating_instructions.pdf

 

The timer mode on this controller is called AUTO. Setting up the mode and time schedule is explained on p13 et seq.

Note that there are two sub-modes. The factory default setting is ECO. This will turn the HP completely OFF overnight which is what you say you want.Though I have some misgivings about that, the alternative is SETBACK where you have control over the overnight temp.

 

14 hours ago, zoothorn said:

Hi BB,

 

no the VRC700 is not in a hot tiny enclosure with the cylinder..

 

Only way I can move the thermostat is buying 30m of cable & running it thru an attic, drill hole in ceiling, run cable down to kitchen/ thermostat there. But this room is SOO damn cold, 2nd coldest (one reason is bc there's no convenient wall to put anything but a single small double rad on: a mini fan heater is FAR better at heating this mostly ininsulated room, than this small rad ever does, or could ever do I reckon). I don't think this is a sensible place to put it myself, as surely just --too-- cold??

 

 

I wonder if moving it to the landing would be an acceptable compromise, at least it would be in a circulation space not shut away.

 

3 hours ago, Nickfromwales said:

Which is why I suggested fitting a stat like mine, as above, which is no more difficult to program than a Casio wristwatch or digital alarm clock.

 

 

You can do this with a Vaillant but you can't connect into the ebus, you need to wire it directly into terminals in the outdoor unit which is not really a DIY job.