Awful CH trouble.

[Sea Chief]

I did wonder if that might be the case. Switching off the indoor unit alone would probably throw some error message and shut the whole system down.

Hi Alec. Just to complicate things.. the install has been done under a welsh govt grant. Now this means I haven't paid for it, which i always take on board & grateful for (am I? I dont exactly know now tbh) but rather hampers me in some aspects.. certainly one reason installers have refused to cooperate.

I did hear from head of govt dept, that I am not the only one whose had noise problems with this system, rather cryptically said, not willing to divulge any more details i sensed. All he does is say 'have a word with next guy down he's the one to go to' etc. Then this chap does the slight threatening 'ok well remove it all tmrw for you' attitude. The installers he oversees.. refuse to communicate. Hence Vaillant is my only viable avenue to try get this resolved. It is their software issue too, simple as imo.

 

[Sea Chief]

A family friend, elderly, has suggested citizens advice bureau. Anyone have opinion on this idea? He also said failing that I need a solicitor who specialises in 'commercial law'.

thanks. sC

 

[Sea Chief]

@MeldrewsMate

outside fan/ compressor unit, problem hydraulic box unit, cylinder (both in spare room 1st floor, which is bang in middle of house).

 

[MeldrewsMate]

...To be honest, its not a case of tweaking the system to suit, or any issue with ability to get it working better, or optimally, or slightly differently...it still comes on overnight). It is deemed to be a fault. Board replacements & their chief of engineer head honcho himself, here, telling me so concludes this..

...It is how i tackle the company...

This is normally a site which concentrates on solving technical problems, you have been referred to Trading Standards if you think it's beyond fixing, however if you are prepared to help yourself a little (which may mean getting up close to this machine when it wakes you), here are some pointers that may help you gain evidence either to work with the installer/manufacturer, or with which to beat them.

You have indicated that the problem only occurs on cold nights:-

There is a function described in your manual on page 27 (frost protection) When the outside air temp is detected to be below 4C the unit will run the compressor and the pump.....IF the differential on the heating pipes is wrong (it doesn't qualify further). You can observe if this is active by looking at status display S34.

Likewise S107 shows if the Heating Overrun is active, here only the pump and fan (outside?) run.
S104 indicates when if the compressor is active.

So...is the noise that wakes you caused by the compressor, the pump, the fan, or a combination?

 

[MeldrewsMate]

The issue is overnight noise. Not from the outside unit (fan, compressor) ..no. Only from the indoor 'hydraulic unit'. Suitcase size box near cylinder, both in spare bedroom. It is this.. a very pronounced whirring pump noise, loud enough to wake me 3 bedrooms away, incessant on-off-on-off bursts 2 am to 6 am..

..it is the -overnight- noise which is the problem due to time it does it, plus the fact that it goes into extra noisy mode during them...

...I know a few things definitely about the noise: it occurs only when outside temp hits 3.5*C & below: screen says 'Heat compressor active' (so the outside fan unit -plus- the problem indoor unit both spring to life, but only one is disruptive): these awful noisy active periods last 10 mins: the silent time between them approx 40 mins: noise is the indoor unit's pump, more specifically engaging at its highest 'rate': it seems to have a few 'gears' ranging from its usual daytime "2nd gear" (just bearable, tho a continual annoying pump whine in the spare room) to a far more prominent "4th gear" high speed mode infuriatingly only heard during these awful overnight 10 minute bursts, prominent enough to be easily heard in every corner of the house (annoying is an understatement: it is prominent enough to wake you rooms away, & infuriatingly audible).

The above is from your first post.
It seem the disturbing noise eminates only from the circulating pump, and this can be greatly mitigated.
The speed of the pump can be adjusted in the Vaillant settings (head?)
The noise through your (radiator?) valves can be alleviated by balancing along with pump speed adjustments.

If Vaillant are able and willing to divert the 'frost protection' reaction to heating only the hot water cylinder then you may find this is much much quieter than sending water through the radiators at 2am. Bridges may have to be rebuilt before you can have an honest discussion with them about doing this/these modification(s).

 

[ianmcd]

I have worked on ASHP but not the vaillant ones, have a closer look at it , I know it will say Vaillant but may actually be made by another company, Im not sure if Vaillant make them themselves or not, if they are actually made by a company and badged Vaillant then contact the manu technical advice

 

[MeldrewsMate]

...to add to thread no.35 above, check that each radiator valve inlet (the one that gets hottest when the heating is on) is fully open, and the balancing restriction is performed only on the cooler of the two rad valves (the return valve). If you have TRVs on the rads then in some circumstances and with some TRVs a reversed flow will cause a noise (not applicable to your 2am though!), but a high flow rate through a 'reverse connected' return valve will cause a constant roaring noise.

 

[Sea Chief]

It was a suggestion mate.
Trying to help is all.
It's between you and Vaillant.
I'm out.
Good luck.

Yes and i can understand in some situations, determining what level the noise is, would be of use. But not here it will only help my adversaries, because the next step on is to say it is 'within acceptable levels'.. just the idea makes my stress levels rise. If it wakes a customer 3 rooms away it is simply unnacpetable & too prominent. I had Vaillant do this very db test on my stairs, to the outside units noise coming into the house. At one stage this was problematic too, but during the day (so nothing in comparison to overnight intrusion) but as heard.. was able to be adressed & a "silencer" fitted, a token gesture to brush me off was the idea.

Trouble is the overnight noise happens overnight.. so no engineer can ever witness it. So in a way good that they will never get any wretched db meter on it. The silencer knocked the outside unit noise into the house down a peg only btw. The word silencer mostly a joke.. but this units noise into house now just about tolerable so I was grateful for them adding it. Some would disagree tho as it still introduces a groaning noise I can still hear it thru every rad & thru thick stone walls. But not suddenly at 4.35 am.

I would just strongly advise against anyone getting one of these Vaillant ashp's. Flat out. Deliberately hidden issues by mfr in this case. And stupidly complicated too.

thx SC

 

[Sea Chief]

...to add to thread no.35 above, check that each radiator valve inlet (the one that gets hottest when the heating is on) is fully open, and the balancing restriction is performed only on the cooler of the two rad valves (the return valve). If you have TRVs on the rads then in some circumstances and with some TRVs a reversed flow will cause a noise (not applicable to your 2am though!), but a high flow rate through a 'reverse connected' return valve will cause a constant roaring noise.

Hi MM. thanks for advice, im happy with the rads doing their thing: theres a bit of a whine, bit of pressurey noise.. but totally normal, totally acceptable. During the day they do this, the outside fan thing adds a bit of a groan, the indoor unit adds a bit of a whine. But, all acceptable, all fine. Im happy.

It is when the damn thing is not running the rads, is when the problem happens in fact. At 3 am, it might say " heat compressor active" & the outside fan coming on, very low level thankfully, plus the awful indoor unit too, very high level unfortunately.. but.. the rads never come on (it is in setback mode, to purposefully deliberately to prevent the rads coming on, from 9 pm to 6.30 am). Probably bc these awful noise bursts/ system active bursts only last 10 mins, maybe its 6 mins each is why the rads dont com3 on: so: it seems to be in some sort of design function to deliberately - not - fire the rads up. You have to contor5 your brain t9 understand for what purpose it is doing these dreadul periods of activity: this alone is exhausting: eg..

The actual function of these awful periods is as much a mystery, as why its doing it, as it is when it only chooses to do it at the most inconvenient time, as is why it chooses to double the noise level during it. Infuriating in every conceivable facet. Even Vaillant do not know what it is doing!! So theres kind of no wonder, in a very slight way as it were, that the fix hasnt been found!! But.. there must be some human input to have chosen this function, designed it, designed the threshold point of 3.5*c to trip i5 into coming on. Ive even said to Vaillant "in theory, please all i need is a '-' sign added before the 3.5*c !!" Ie it once in a blue moon ever coming on, likely almost never registering MINUS 3.5*c.

 

[Sea Chief]

You are all very kind to read my spiel. I really am grateful for any ideas. Apologies again for long posts. Ill try short uns from now on, as ive fully explained (and some) every tiny bit of the problem now.

Im almost too exhausted to do this, to ask for more help. It really is my last gasp. I think it has to be solicitors approaching in the distance as last option.

I do fleetingly consider the idea of some diy addition, in order to simply interrupt the signal from a to b. Now, i know the "vrc 693 "sensor ( might be known on here) is hard wired to this dreaded indoor box unit.

In theory, if a simple Minus sign - could - be added, in theory in this sensor.. but its an implausible idea.

But sheer exhaustion prevents the idea progressing. Thx SC

 

[MeldrewsMate]

In that noisy indoor unit there will be a refrigerant to water heat exchanger (almost silent), and a pump to take that heat away (to your rads, or other heat load). Clearly if the water cannot circulate because of some external valve (no mention of this, nor photos) then that water may well flow over a by-pass arrangement. This could be the noisy element.

I will back out now, I have no more to add. Perhaps you need to employ a technician advocate to deal with Vaillant on your behalf.

 

[MeldrewsMate]

...as ive fully explained (and some) every tiny bit of the problem now.

Clearly not all and every bit....

Now, i know the "vrc 693 "sensor

Look into your manual, the resistance readings are there for that sensor, so if you wanted to 'doctor' the detected temperature there are means to do so, at the expense of risking damage to your system and invalidating any warranty.
Again, speak/write to Vaillant about your options in changing this frost protection function (setting).

TBH it seems crazy to use the external temperature reading to switch on the internal heating "to protect the heating circuit" when the only parts exposed to the frost outside are electrical items and refrigerant, both of which can survive much lower temperatures than 0C.

Ever thought of moving the external sensor somewhere warmer?

 

[Razor900]

Does it start making noise at exactly the same time every night or is it variable?

Have you tried turning the cold feed off to the hot water cylinder in case there is a leak on the pipework somewhere leaching heat out of the cylinder overnight causing the unit to fire?

I get you're stressed but the manufacturers do read these forums and it does appear that Vaillant have tried to work with you to resolve the issue so it may be more diplomatic to keep them onside...

 

[Alec_t]

Just curious. What settings do you have for set-back temperature, eco mode, party mode?

 

[Sea Chief]

You could also look at sound proofing around whatever is making the noise, it shouldn't take much for a big improvement.

If possible can you take a photo of what is making the noise and how it is attached to whatever surface it is on?

Something like dynamat might be suitable, something with a bit of mass to it not lightweight like rockwool.

Swwils. Great idea, had thought of this, alot of faff & time, defo a latter resort option.. ie if i could just get it to shut the fgk up/ will explore every possible route on this avenue 1st tho you see. One remote possibility is moving the damn unit to back door area. But im not entertaining either your option or this just yet.

Appreciated SC