ASHP: lagging pipes in loft

albyota

Getrr, what is it doing at the moment, do you have any heat going into the UFH?

gterr

albyota wrote: »

Getrr, what is it doing at the moment, do you have any heat going into the UFH?

Really interesting!

First turned on rad valves half way. They all got hot. Then turned rad time clock from AUTO to OFF. Initially all went quiet (a pump must have stopped). Then, the lever on that motorised valve above the manifold moved of its own accord from AUTO a little way towards MAN. A pump started up, for just about a minute, then the lever moved back to AUTO and now everything has gone deadly quiet.

Checked the U/F timer stats and nothing was asking for heat, so I turned a couple up, so they should be demanding heat now. None of the actuators on the manifold have opened, and there is still an eerie silence!

The heat pump fan and compressor have just started up.

The silence is actually rather lovely, but I fear that all is not well!

Edit: Ignore that bit about me adjusting the U/F timer stats: I may be misunderstanding how these work.

The downstairs bedroom stat just showed it was asking for heat. A pump came on, the actualtor opened as did the flow indicator. Ran for a couple of minutes then closed down again. Bedroom now up to temperature.

Will see if I can naturally cool another room and see if the U/F comes on.

lovesgshp

Tomorrow Gterr, change the room sensor influence to 5, and check the units used, as we need to start to compare the loads.

lovesgshp

gterr wrote: »

Really interesting!

First turned on rad valves half way. They all got hot. Then turned rad time clock from AUTO to OFF. Initially all went quiet (a pump must have stopped). Then, the lever on that motorised valve above the manifold moved of its own accord from AUTO a little way towards MAN. A pump started up, for just about a minute, then the lever moved back to AUTO and now everything has gone deadly quiet.

Checked the U/F timer stats and nothing was asking for heat, so I turned a couple up, so they should be demanding heat now. None of the actuators on the manifold have opened, and there is still an eerie silence!

The heat pump fan and compressor have just started up.

The silence is actually rather lovely, but I fear that all is not well!

Edit: Ignore that bit about me adjusting the U/F timer stats: I may be misunderstanding how these work.

The downstairs bedroom stat just showed it was asking for heat. A pump came on, the actualtor opened as did the flow indicator. Ran for a couple of minutes then closed down again. Bedroom now up to temperature.

Will see if I can naturally cool another room and see if the U/F comes on.

Seems like we are getting somewhere, which is good news

albyota

From the way I think the plumbing is configured, all the heat initially will be coming from the thermal store / buffer tank, so as a thermostat calls for heat, either a motorised valve / UFH actuator opens which in turn switches on the relevant circulating pump to circulate water round the circuit, at the same time, or shortly after the heat pump would be called into action due to a sensor fitted in the store after dropping temperature due to it supplying rads etc. see if this fits with how you see it working.

gterr

Can confirm that U/F timer stats are behaving as they should. Demand for heat is followed by pump coming on near the manifold, actuators opening and flow indicators moving. Floor in tiled areas getting warm. Flow and return pipes (near manifold) both warm (were initially stone cold when I switched off the rad timer).

Pump switches off again once U/F coils have done their stuff.

Whole system still nice and quiet compared to when the rad timer is on.

Geotherm:
Yes, I can adjust room temp influence to 5 tomorrow. The sensor is in the hallway which is a closed section of the house, and is usually the warmest place in the house as a result. I have set its U/F timer stat to 17 C. Should I turn it up? Or should I turn down the target room temperature in the top menu of the HDWU Rego to 17 C to match. Or does it not matter? I am conscious of all these stats fighting one another!

lovesgshp

gterr wrote: »

Can confirm that U/F timer stats are behaving as they should. Demand for heat is followed by pump coming on near the manifold, actuators opening and flow indicators moving. Floor in tiled areas getting warm. Flow and return pipes (near manifold) both warm (were initially stone cold when I switched off the rad timer).

Pump switches off again once U/F coils have done their stuff.

Whole system still nice and quiet compared to when the rad timer is on.

Geotherm:
Yes, I can adjust room temp influence to 5 tomorrow. The sensor is in the hallway which is a closed section of the house, and is usually the warmest place in the house as a result. I have set its U/F timer stat to 17 C. Should I turn it up? Or should I turn down the target room temperature in the top menu of the HDWU Rego to 17 C to match. Or does it not matter? I am conscious of all these stats fighting one another!

Set the internal stat to 19C after you check the 24hr usage tomorrow. We have to do this step by step, to get the best setup.

gterr

Many,many thanks to everyone who is helping us with this.

Signing off for the night now. Out for most of tomorrow but will post meter readings first thing then make the adjustments Geotherm has requested, then report back tomorrow night.

lovesgshp

albyota wrote: »

From the way I think the plumbing is configured, all the heat initially will be coming from the thermal store / buffer tank, so as a thermostat calls for heat, either a motorised valve / UFH actuator opens which in turn switches on the relevant circulating pump to circulate water round the circuit, at the same time, or shortly after the heat pump would be called into action due to a sensor fitted in the store after dropping temperature due to it supplying rads etc. see if this fits with how you see it working.

You are correct, Albyota. We just have to get the balance in the system right.Looks like we are getting there, so I dont have to get a flight to Skye unfortunately

gterr

Good morning,

Here are the meter readings from Skye:

25/09/2012 10pm 562
1/10/2012 10pm 2884 (2332 units in 67 days, av. 35 units per day)
2/12/2012 10pm 2949 (65 units in last 24h, 1 degree outside)

Pipes lagged in loft and outside:
3/12/2012 10pm 2984 (35 units in last 24h:, 5 degrees outside)
4/12/2012 9am 3001

Rads on: rad timer off. 7pm:
4/12/2012 7pm 3026
4/12/2012 10pm 3032 (48 units in last 24h, 2 degrees outside)
5/12/2012 8.30am 3047

Currently fan, compressor, hot water, and auxiliary electric heater are all on. Four U/F coils open, four rooms below target temperatures. Outside temp 2 degrees.

Not sure why hot water heater and auxiliary elec heater are on: DHW temp is now at 60 C and rising (usually this between 50 and 55 C) nobody has used any hot water yet today. Pasteurisation should only be happening once a week on Wednesday at 7pm. However, I did notice an extra pasteurisaion step on Monday. Currently the 'pasteurisation' indicator symbol is not on, just the symbol for hot water heating.

Will now make the adjustments Geotherm requested.

I will not be going out today as originally planned, so will monitor this board.

And Geotherm: the offer of flights + hol still stands!