UFH Return Temp Problems

[jack]

1 hour ago, Pete said:

when we lit the fire (5KW) it used to send me to sleep!

 

Oxides of carbon will do that to you! 

[Pete]

2 hours ago, ProDave said:

OOOh I never knew that.

 

I had always quoted the whole message then deleted the bits of it I did not want to include.

 

2 hours ago, jack said:

 

Works like that on PC too (as I just learned!)

 

2 hours ago, PeterStarck said:

Just highlight the bit of text you want to quote and a 'Quote Selection' box comes up.

I'm not as lonely in this world as I thought!! Thanks chaps

[joe90]

14 minutes ago, Pete said:

I'm not as lonely in this world as I thought!!

 

Group hug!,,!    (Oh that’s not allowed anymore ?)

[SteamyTea]

3 hours ago, joe90 said:

Oh no your not, join the queue. I use an iPad. Touch the beginning of what you want to quote, drag to include text and a “quote’ thingy comes up. (No idea with any other devise).

And on my very cheap Android phone.

[andy]

So, here you go - happy new year, here's my Samsung settings... sorry there are so many pics, did I mention I detest this controller?

 

Edited January 12, 2021 by andy

[swisscheese]

Thanks Andy,

Comprehensive.

I'll double check against mine, but on first look, very similar.

 

[Chriswills]

Any point having a mixer valve with ASHP?

The HP will control the flow and return temps and they are low anyway not like a boiler that needs to control the Max heat into the floor. 
Ive never had a mixer. 

[joe90]

2 minutes ago, Chriswills said:

Any point having a mixer valve with ASHP?

Depends on the set up, my ASHP only has one temp setting to deliver heating and DHW, I set it to 47’ which is enough fir DHW, it heats a buffer to 35’ for the UFH and a mixer on the manifold brings the temp down to 25’.

[PeterW]

9 minutes ago, Chriswills said:

Any point having a mixer valve with ASHP?

The HP will control the flow and return temps and they are low anyway not like a boiler that needs to control the Max heat into the floor. 
Ive never had a mixer. 

Absolutely a requirement. See this regularly and they can overshoot and they can also not modulate down far enough. The modern ASHP refrigerants can hit 62°C too, they are borderline boiler temperature. 
 

A mixer also gives you the pump which is essential - most issues with UFH come back to lack of flow and as soon as you start with 2 floors and multiple manifolds you need to manage the flows properly. 
 

 

[Chriswills]

I don’t use my HP for DHW so it’s set to return temp of 35 C, so nothing to mix really. 
I have a pump at the buffer tank side which continually pumps whether calling for heat or not but more often than not the rads always need some flow

[andy]

Right - made time to get Garfana up on my Raspberry Pi.  The flow 1-Wire sensors are in the loft, so we have data now ?:

[andy]

More data, this was yesterday morning flow and return temps - alas I don't yet have external temp sensor but it was around zero first thing and icy (outside).  I am wondering if a buffer tank might be a good call here but not a decision I will rush into.  As you can see the time spent either defrosting or recovering is considerable:

 

Compare that with the afternoon where ambient temperature is higher:

[swisscheese]

Andy, I don't have the data to back this but this is exactly what I see with the Samsung unit, essentially anything around 3 degrees or below.