Evening.
Father in law had an extension, this involved a extended single storey rear ext, approx. 4M x 4M heated by UFH.
A new boiler (Vaillant Ecotect Pure 825. No real idea why he accepted a combi, when he has a tank and solar which surpluses to hot water tank immersion, but moving on....
Adaptions - as pump was in airing cupboard in loft with hot water tank, new boiler has self contained pump, UFH manifold under boiler in kitchen cupboard, a bypass valve is fitted as shown in diagram between unzoned flow and Hot Water tank return in loft but set, I assume at default min 0.1bar. Loft header tank removed from boiler pipework as now pressurised.
Problems:
Keeping brief, the build went ok. Plumbing and central heating was fine until the older of the 2 man team was admitted to hospital ill and later died. Very unfortunate. Anyway, most of the build and 1st and a lot of second fix was done when that happened, but no commissioning / set up / wiring up.
Once the boiler was reconnected and put on, the remaining guy struggled to set it or even get it operating, with the existing nest thermostat and new heatmiser UFH thermostat.
He did get it working in end, but when cold weather hit in Decemeber, the heating in the house was "poor".
When I investigated I found:
Trying to improve downstairs rad heat up and system operation.
I suggested thermos rad valves, at least upstairs, but FIL says why, when not needed before? Even regardless I still said they would improve control and efficiency.
Is the UFH single loop pump robbing flow set at 3 and on constant speed mode. Could that cause lack of flow for simultaneous HW tank coil heating? UFH on separate pump and single loop manifold - but flow has to come from main CH flow regardless?
The hw tank used to heat with rads and hot water cyclinder before on 12 year old baxi straight boiler, vented, separate pump (one of the first condensing ones).
I est. rads upstairs and downstairs combined do not exceed 10kwh.
UFH can’t be more than 1kwh (one loop) small room size - probably doesn't cover bathroom as towel rail installed.
Indirect hot water tank coil. No listed output on sticker on tank, only Litres and dimensions, but guess 8 or 9kwh. Takes about 1hr to heat to 60C and is 145L.
The installer is coming back Wednesday to try and improve but on the track record he will need some help to get it operating, at least as well as it used to.
I’m also left wondering, apart from possibly altering settings on the UFH wilo pump and lowering the curve setting, does the system now need a gate valve on the hot water tank return to slow down the tank flow and balance?
Thoughts? Thanks for any help. Most appreciated.
Father in law had an extension, this involved a extended single storey rear ext, approx. 4M x 4M heated by UFH.
A new boiler (Vaillant Ecotect Pure 825. No real idea why he accepted a combi, when he has a tank and solar which surpluses to hot water tank immersion, but moving on....
Adaptions - as pump was in airing cupboard in loft with hot water tank, new boiler has self contained pump, UFH manifold under boiler in kitchen cupboard, a bypass valve is fitted as shown in diagram between unzoned flow and Hot Water tank return in loft but set, I assume at default min 0.1bar. Loft header tank removed from boiler pipework as now pressurised.
Problems:
Keeping brief, the build went ok. Plumbing and central heating was fine until the older of the 2 man team was admitted to hospital ill and later died. Very unfortunate. Anyway, most of the build and 1st and a lot of second fix was done when that happened, but no commissioning / set up / wiring up.
Once the boiler was reconnected and put on, the remaining guy struggled to set it or even get it operating, with the existing nest thermostat and new heatmiser UFH thermostat.
He did get it working in end, but when cold weather hit in Decemeber, the heating in the house was "poor".
When I investigated I found:
- new towel rail in new bathroom lockshield closed – no heat
- Boiler set to 64C flow (hoping for condensing based on return temp I suppose)
- DHW temp set to 55C but could not get more than 40C out of thermostatic valve in new bathroom due to Cold Water flow being so high.
- Blend valve on underfloor heating set at 4.5, with a flow showing 52c and retrn 39C whilst still in later stages of heating. Seemed too high esp with Karndean floor coverings.
- No heat on downstairs radiators at all when UFH + Rads + Hot Water tank heating.
- Further investigation showed heating poorly balanced but even after balancing rads, downstairs rads not operative with hot water tank heating
- UFH pump Wilo Para 25/6 -43/SCU set to contant speed and curve 3.
Trying to improve downstairs rad heat up and system operation.
I suggested thermos rad valves, at least upstairs, but FIL says why, when not needed before? Even regardless I still said they would improve control and efficiency.
Is the UFH single loop pump robbing flow set at 3 and on constant speed mode. Could that cause lack of flow for simultaneous HW tank coil heating? UFH on separate pump and single loop manifold - but flow has to come from main CH flow regardless?
The hw tank used to heat with rads and hot water cyclinder before on 12 year old baxi straight boiler, vented, separate pump (one of the first condensing ones).
I est. rads upstairs and downstairs combined do not exceed 10kwh.
UFH can’t be more than 1kwh (one loop) small room size - probably doesn't cover bathroom as towel rail installed.
Indirect hot water tank coil. No listed output on sticker on tank, only Litres and dimensions, but guess 8 or 9kwh. Takes about 1hr to heat to 60C and is 145L.
The installer is coming back Wednesday to try and improve but on the track record he will need some help to get it operating, at least as well as it used to.
I’m also left wondering, apart from possibly altering settings on the UFH wilo pump and lowering the curve setting, does the system now need a gate valve on the hot water tank return to slow down the tank flow and balance?
Thoughts? Thanks for any help. Most appreciated.