Turning on UFH first time this year

[ADringer]

Hi all,

 

We had our UFH (75mm screed with engineered wood + ASHP) installed this time last year and turned it on slowly when we first started using it.

 

Now it's coming round to turning it on again, I was wondering if we need to turn it on again slowly each year or is this only needed the very first time? I've tried googling but can only find information about the very first time.

 

For context, I'm on Intelligent Octopus tariff. When it's between 10-15C I was just running the ASHP at 40C for 3 hours overnight and this was enough to keep it warm for the day. Would going straight to 40C for that duration be ok or is that a shock for the slab? I assume the wood wouldn't be an issue as it will take a while to for the slab to warm up before getting through to the wood.

 

Thanks!

[ProDave]

Just turn it on.  the slab won't go straight to 40C the laws of physics means it will heat up slowly.

 

I turned ours on yesterday.  For all the southerners basking in unseasonably warm temperatures, spare a thought for the north of Scotland where it had been raining hard non stop for 48 hours and the temperature outside was about 7C

[JohnMo]

To add to what @ProDave says, the first heat cycle may take quite a bit more energy than subsequent ones, as you need to heat your floor more the first cycle to get it up to temperature.

 

My heating went on on Saturday, I too have had steady 7 degs and pouring rain. Up to 12 degs today!

[SteamyTea]

46 minutes ago, ADringer said:

We had our UFH (75mm screed with engineered wood + ASHP) installed this time last year and turned it on slowly when we first started using it.

I should be fully cured now, and had over a 100 heat cycles already, so should be alright.

As an experiment, you could set your flow temperature to 35°C, see if it saves some energy and still makes the room comfortable.

 

@JohnMo, @ProDave

48 hours of rain is not unusual here.  You East Coasters are just not used to rain.

But were have had two days of bikini weather, 22°C, been better than August, which was dreadful weather.  Half term week soon, so weather will break then.

 

Perranporth Beach yesterday.