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My (rotten) ASHP. Update.


zoothorn

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Ok so auto means it is timed. So it is running two or three heat periods and a couple of hot water periods. 
 

First off .. if it is only dropping to 18c on the off period then it is the reason you have issues overnight - there is only one setback temperature. I wonder if they have only set it to 18c on setback. 
 

Secondly that hot water setting is pointless - it’s not like a kettle and a new tank will hold hot water for a long time. You would be better having it come on for say 2 hours when the heating finishes in an evening - 9-11pm assuming you can’t have it on overnight due to noise, and then have it boost again 11-12pm to top it right up. Ideally you would load shift that to the overnight tariff if you had E7. 
 

I think when you get Vaillant out to it to sort the pressure loss I would ask them to walk you through the settings and what it is set to as without seeing it first hand or photos of each setting I’m struggling.  

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A couple of points.

 

I think we determined that although @zoothorn unit is a split unit, it has the gas compressor in the outside unit, so all that i in the inside unit is a heat exchanger, water circulation pump, expansion vessel and some controls.  Apart ftom the pump in there it should be no more noisy than my monoblock unit.

 

+1 to the time settings being wrong.  Before you next get Vailant out, write down on a bit of paper what times you want the heating on and what temperatures you want and ask them to set it to that.

 

For instance my heating comes on at 6AM and stays on all day until 9PM with a set temperature of 20 degrees.  Of course that does not mean it runs all day unless it is really cold, it will turn on and off as the room thermostat dictates but after 9PM will not come on even if the house goes cold.

 

In your system you would achieve that by setting the temperature between your required times to 18 degrees or whatever you are comfortable with and setting the night temperature to say 14 degrees. 

 

If you want to ensure it NEVER comes on at night, even when it's damned cold, set the night time temperature to 5 degrees, but then you must accept after a really cold night it might take longer to heat the house in the morning. That is the price you pay for a silent night.

 

Now hot water time settings.  One feature of heat pumps is they usually only heat the rooms, OR hot water, never both at the same time.  I have my hot water set to come on at 11AM and then stay on until 8PM  It is not often anyone showers here in the morning but if they do there is enough hot water for one shower in the morning still in the tank.  the not coming on until 11AM is to ensure maximum use of solar PV and we have some shading issues that mean much before 11AM generation is low due to the shading,

 

Now your dilemma between wanting a warm house when you get up and wanting it silent at night, is it WILL need to come on before you get up.  So you have to accept a time in the morning where you are prepared to accept the noise it makes to warm the house before you get up.

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I don't understand a few things, one of which is as I just find now, 9.10am. Rads only just 'warm' (btm of them cold-tepid). The controller big number is 19*, my desired carried over from last night, 20*. So heating been on from 7.30am and still on getting it up to 20*. But rads not even hot. I was just in my new extension upstairs room, all new insulation, & standing big-ass-on-bigass-rad.. I could feel a cold nip on my knees w'me long johns on. Room is only tepid, certainly not warm.

 

I sometimes notice this, but only AM. PM when it hasn't had a prior 'idle' block of hours, & I dial in 20* after my stoating, it gets rads hot in 1 hr, my top room gets fairly warm (workshop below- gets actually very pleasant/ toasty even). So a discrepency here, &, I think directly linked to it -not- being designed to be idle at night.

 

Now in here 9.10am today, I'm in a new room akin to one of ProDave's insulated one, but I'm not warm. The thermostat's 2 rooms away, perhaps daftly under normal house rules, on the backside of cylinder cupboard: so actually in a fairly warm spot (defo warmest in house now). I was gonna move it to a convenient place thinking its too warm for it here, to kitchen, as suggested (normally a good place/ access etc) but now thinking its better where it is, as it means the heating won't be going on/ off/ on alot more driving me mad (& costing me), bc my kitchen is a very cold room.

 

It just perplexes me every day this thing. Its like living with an infuriating being you don't know what's round the corner. This might well ring a few bells with some of you.

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4 minutes ago, ProDave said:

 

I think we determined that although @zoothorn unit is a split unit, it has the gas compressor in the outside unit, so all that i in the inside unit is a heat exchanger, water circulation pump, expansion vessel and some controls.  Apart ftom the pump in there it should be no more noisy than my monoblock unit.

 


This isn’t the case and you do get more noise from an internal split. Same with A2A units. 
 

5 minutes ago, ProDave said:

your system you would achieve that by setting the temperature between your required times to 18 degrees or whatever you are comfortable with and setting the night temperature to say 14 degrees. 


Can’t do that with the unit he has - it only has 2 temperature settings, the heat setting and the setback. Both have to be the same in on/off periods so basically whatever temperature is “off” between 9am and 12 noon for example is the same setting between midnight and 6am. 
 

5 minutes ago, zoothorn said:

So heating been on from 7.30am and still on getting it up to 20*. But rads not even hot.


I don’t think it is on for long enough in a morning. I think you need it to come on from 6:30am to 9:30am for a while and see what difference that makes. 
 

Also, dialing it up and down isn’t helping - these are “smart” controls that use the outside temperature to work out when the target temperature is needed to be reached and I think you’re changing it and expecting it to respond instantly the same way gas does. 
 

I think you may need a compromise here and set the whole house setting to 18c from 6am - 9pm and if it’s “chilly” then boost it up to 20c using the dial when you want that.

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1 minute ago, SteamyTea said:

Read the (expletive deleted) manual, page 13.

 

RTMF.jpg


I think his point is that it doesn’t have a third temperature setting - so on / daytime setback / nighttime setback, it’s like a lot of the UFH controllers that only cope with two settings although if it is “off” at 18c then it will be trying to maintain that at night and it will run overnight. 

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4 minutes ago, PeterW said:

I think his point is that it doesn’t have a third temperature setting

Yes, but it is what it is.  My car does not have an MP3 player, I live it it.

With this old thermally leaky house, a third temperature/time option is not necessary.

It is also just a matter of changing the controller to a better one.

Sooner or later, Zoothorn needs to take ownership of it and sort it himself.  We have pointed out just about as much as we can, and just get the same 'finger pointing' response back "it is there fault".

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11 minutes ago, PeterW said:

Can’t do that with the unit he has - it only has 2 temperature settings, the heat setting and the setback. Both have to be the same in on/off periods so basically whatever temperature is “off” between 9am and 12 noon for example is the same setting between midnight and 6am. 

 

...and the diagram on page 25 may help illustrate this as it can get a bit confusing just written down if you're not familiar with this method of control:

 

2091168237_Screenshotfrom2020-11-0109-49-43.thumb.png.4ce37d0279ad2730bf61801a694181f5.png

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45 minutes ago, PeterW said:

Can’t do that with the unit he has - it only has 2 temperature settings, the heat setting and the setback. Both have to be the same in on/off periods so basically whatever temperature is “off” between 9am and 12 noon for example is the same setting between midnight and 6am. 
 

So to ensure a silent night time, set the set back temperature to 5 degrees and accept if there is an off period in the middle of the day the house might get very cold.

 

If you can't accept a very cold house in the middle of the day then make the morning heating time stay on for longer and make the afternoon heating time start earlier.

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1 hour ago, zoothorn said:

I don't understand a few things, one of which is as I just find now, 9.10am. Rads only just 'warm' (btm of them cold-tepid). The controller big number is 19*, my desired carried over from last night, 20*. So heating been on from 7.30am and still on getting it up to 20*. But rads not even hot. I was just in my new extension upstairs room, all new insulation, & standing big-ass-on-bigass-rad.. I could feel a cold nip on my knees w'me long johns on. Room is only tepid, certainly not warm.

 

 

What are your hot water times set to?

 

As I tried to explain, when it starts heating the hot water it will STOP heating the rooms for the duration of that.  So if your hot water heating has come on, your radiators will go off for a time.

 

On my unit you can set how long the hot water function stays on and then the time before it does more hot water heating.  Mine is set to 30 minutes on (the default setting) and then 30 minutes off (the default I think was an hour)  But this is a more complicated setting than just setting programmer times.

 

I believe the logic in this timed arrangement for hot water is partly not to deprive the house of space heating for too long at a time (that would not be an issue in my house) and also because the heat pump is working harder when heating hot water, by limiting the HW time will reduce the likelihood of it needing to defrost.

 

Different units treat this in different ways so ask the guys when they come round to explain how your unit deals with this and agree between you how you would like it set to operate.

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2 hours ago, PeterW said:


I think his point is that it doesn’t have a third temperature setting - so on / daytime setback / nighttime setback, it’s like a lot of the UFH controllers that only cope with two settings although if it is “off” at 18c then it will be trying to maintain that at night and it will run overnight. 

 

I think this is what I'm getting at, yes. I'm trying to repeat what both Vailant engineers told me, but difficult to do ad verbatim.

 

The manual I was told was unfit for purpose: tbh I'm amazed you gleaned what you have from it, as to me its consistantly double-dutch. Actually not having the huge printed manual overwhelming you, using the online version (I didnt know existed- thx) might be clearer to interpret.

 

I'm really confused by the discussion now! its over my head.

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2 minutes ago, zoothorn said:

The manual I was told was unfit for purpose


I agree the installer manual is (I’m not posting a link to that ..!!!) but the user manual is pretty decent tbh and no worse than any other controller manual I’ve seen recently. 
 

So as not to confuse, if you want to PM me the photos of the settings (if you can get to them) I can have a look at what it’s set to. 

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1 hour ago, ProDave said:

So to ensure a silent night time, set the set back temperature to 5 degrees and accept if there is an off period in the middle of the day the house might get very cold.

 

If you can't accept a very cold house in the middle of the day then make the morning heating time stay on for longer and make the afternoon heating time start earlier.

 

Yes understood about the silent night idea- thanks.

 

I was told its better, and I think designed to be used, by manually adjusting the rad temp as suits you whenever you want (with the big rotary dial so prominent, and spinning it so quickly altering the desired temp- a good, simple & very userfriendly design- suggesting this operating method instrinsicly recommended: altho Mrs Miggins won't know about it, nor did I until Vailant chaps told me this way).. rather than having pre-set blocks of heating times the old skool way. I'm pretty sure the Vailant chaps said this was the way its designed to be used anyway.

 

Its certainly convenient when you're here, as I'm always here working from home: maybe not so for a 9-5 worker away during day?

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5 minutes ago, PeterW said:


I agree the installer manual is (I’m not posting a link to that ..!!!) but the user manual is pretty decent tbh and no worse than any other controller manual I’ve seen recently. 
 

So as not to confuse, if you want to PM me the photos of the settings (if you can get to them) I can have a look at what it’s set to. 

 

Many thanks indeed Peter- I'll aim to do this in a couple of days/ total scramble on extention last bits now.

 

The manual I have might be different, that one might be updated, I'll dare having a look in time.. but mine has clearly had a german-english translate function used, agreed by Vailant chaps, meaning sentences are consistantly atrociously hard to decipher. Its an abomination.

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1 hour ago, ProDave said:

What are your hot water times set to?

 

As I tried to explain, when it starts heating the hot water it will STOP heating the rooms for the duration of that.  So if your hot water heating has come on, your radiators will go off for a time.

 

On my unit you can set how long the hot water function stays on and then the time before it does more hot water heating.  Mine is set to 30 minutes on (the default setting) and then 30 minutes off (the default I think was an hour)  But this is a more complicated setting than just setting programmer times.

 

I believe the logic in this timed arrangement for hot water is partly not to deprive the house of space heating for too long at a time (that would not be an issue in my house) and also because the heat pump is working harder when heating hot water, by limiting the HW time will reduce the likelihood of it needing to defrost.

 

Different units treat this in different ways so ask the guys when they come round to explain how your unit deals with this and agree between you how you would like it set to operate.

 

12-1pm, and 5-6pm. Set by Vailant chap for me, 1st asking how I wanted it (I had no idea- so just told him of my minimal useage in general). He put these two minimal (afaik) periods in mainly to keep the dreaded noise issue to as mimimal as poss/ least problem times during my day. And to not coincide with time I want heating on, as a general rule of thumb (IE I told him 'I get in from stoating 6pm lets just say'). I didn't want noise 10-11pm as he 1st suggested as a good time for one period (presumably so piping hw 1st thing).

 

thanks zoot.

 

Now the pump's been replaced, in theory I could legthen these times. But if I find HW ok as is/ I'm happy leaving it be.

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2 minutes ago, joe90 said:

If it makes you feel any better my controller hand book might well have been written in Chinese fir all I know (and Jeremy with the same controller had problems fathoming out his as well).

 

 It does. I have tried & tried with mine, cup of tea a big sigh & an hour put aside to really get to grips with it. But a few pages in & I'm at a total loss understanding almost all of it, feeling stress & mild panic starting.

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1 hour ago, zoothorn said:

 

 It does. I have tried & tried with mine, cup of tea a big sigh & an hour put aside to really get to grips with it. But a few pages in & I'm at a total loss understanding almost all of it, feeling stress & mild panic starting.

I told my students to read until they did not understand it.

Then start from the beginning again.

Eventually it sinks in.

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4 minutes ago, SteamyTea said:

I told my students to read until they did not understand it.

Then start from the beginning again.

Eventually it sinks in.

 

I've read it a few times until I don't understand it ST.

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3 minutes ago, zoothorn said:

 

I've read it a few times until I don't understand it ST.

Then keep going, it eventually works.

 

Purely from an educational academic viewpoint, reading is not a very successful way to learn things for most people.

But as you have no choice, keep reading.

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6 hours ago, SteamyTea said:

Then keep going, it eventually works.

 

Purely from an educational academic viewpoint, reading is not a very successful way to learn things for most people.

But as you have no choice, keep reading.

 

ST/ anyone. I can't work out what's happening at the moment here. Its 8.15pm, I dialed in my usual 20.5* at 6pm (from my day temp I put at 18*) & the house isn't warm, I'm feeling the cold in my legs, & the rads I notice are just lukewarm. Just like today AM.

 

The current temp on the controller is 20*, the outside temp is a very mild 14*.

 

Is the fact that the outside temp is 'warm' & the thermometer is measuring this, &, does it adjust the radiator temperature accordingly?

 

This is the only plausible reason why I do not have hot rads. I just don't understand the way this outside thermometer interacts with the system, & what I get as a result, the temperature of the radiator, &/ or for how long its on (Ive no idea if it interacts with one, or both of these factors).

 

Thjanks- zoot

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4 minutes ago, PeterW said:

It’s making sure it doesn’t over shoot the 20.5 you’ve set. 20-20.5 is very fine hysteresis so the unit will slow down. Put it to 22c and see what happens. 

 

But I see this lukewarm-only rads from 6pm to now. No change, constantly the tops warm (& btms actually cold).

 

--

 

Do you know how the outside thermo interacts with the system Peter?

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