Grant R290 Fan Noise

[MrW (Mike Whitby)]

@twarms

I seem to be able to adjust fan speed through the H FAN SPEED settings and have dialled down the 0 setting to 575 and the 1 setting to 600

Oh that’s good news then, but strange @Dave_Storey that these settings don’t work for you, and they definitely don’t after your ASHP firmware update?

@twarms

I wonder by altering these figure whether other parameters (Compressor HZ, pump speed, etc) modulate in line as I assume they do in silent mode or whether this is simply a blunt tool to reduce fan speed for reasons of noise.

Unsure there, I’m assuming they are a blunt instrument but I may be wrong

@twarms

I notice that altering the fan speeds (or at least the two I’ve adjusted) has no effect on calming down the units operation in defrost when the flow rate spins up to the noisy 36l/m and the fan ramps up to 650+ . I assume there is simply no way to modulate the units behaviour in defrost..?

Are you definitely referring to defrosts? I’m surprised you got any last night! I didn’t but may be it’s milder here. Well, I did get one I suppose which is when the DHW was charging which does go high very briefly, see screenshot below:

You mentioned pipes reverberating, is it a banging noise? My installer fitted a three way valve which was not adequate so they had to replace it, if you’re getting banging then maybe read Grant R290 Noise During DHW.

@twarms

All was good until the dreaded defrost cycle with flow rate of 36l kicked in at 2.30am and again at 5.30 making an otherwise peaceful night difficult..

Sorry to hear it, I hate things like that. Do you have the Open Energy Monitor? Would be interesting to look at your graphs.

@twarms

As of yet I haven’t played with the pump speed settings but again I’m guessing this won’t alter anything in defrost but might possibly make the unit ‘waking’ from a simple night set-back (with blockade on) less noisy..?

Unsure there, I’ve not played with or worried about pump speeds, mine seem fine (pipe noise is tolerable or silent), re fan noise I assume (maybe incorrectly) that it uses one of the H FAN SPEED settings when doing a defrost, but I guess that doesn’t help with pump speed.

Re blockade - I don’t think that would affect anything, it just stops the pump when the circuit isn’t calling for heat I think.