ChantalA

thank you,will let you know how it goes once sorted. !

Also where in the system should the mixer valve be installed. It is clear the system needs one!

Hi Peter, so how do you wire the nest to control the UFH Pump, do you need some special valve? Thanks

Thanks John, the real big difference is that your thermostat is wired to your 2 port valve on the UFH supply from the cylinder, not to the boiler, which makes a lot more sense to me! the question now is whether i can do that with a google nest!

my manifolds aren't easy to access, but i can tell you that they are straight tubes in and out with the floor pipes attached,there are absolutely no valves dials or controls except the flow rate ones, so I can't tell what the temp is at the input and output stages. I am on bottled gas ? The buffer is direct plumbed to the boiler and has a coil inside. it is a closed circuit between the two. I also think the pump to UFH is more powerful than the pump in the boiler.. So in this scenario would a mixer value help in the mix... perhaps removing the buffer, adding a mixer value, have the boiler running at the optimum which I believe is 56 degrees with a mixer value keeping the water temp through the UFH at a constant 40 degrees? If the buffer tank wont ever get to temp because it is being drained by the UFH pump, the boiler is going to be running constantly hence the gas consumption... or have I got this all totally wrong??? Cheers Chantal

no idea who installed it... but the buffer is direct plumbed to the boiler and has a coil inside. it is a closed circuit between the two. So in this scenario would a mixer value help in the mix... perhaps removing the buffer, adding a mixer value, have the boiler running at the optimum which I believe is 56 degrees with a mixer value keeping the water temp through the UFH at a constant 40 degrees? If the buffer tank wont ever get to temp because it is being drained by the UFH pump, the boiler is going to be running constantly hence the gas consumption... or have I got this all totally wrong??? Cheers Chantal

Sorry - 60% water being added to it probably shows my ignorance here... I meant pushed through from the boiler to the coil to heat the water up, sorry! I also think the pump to UFH is more powerful than the pump in the boiler.. Hope these help... So in this scenario would a mixer value help in the mix... perhaps removing the buffer, adding a mixer value, have the boiler running at the optimum which I believe is 56 degrees with a mixer value keeping the water temp through the UFH at a constant 40 degrees? If the buffer tank wont ever get to temp because it is being drained by the UFH pump, the boiler is going to be running constantly hence the gas consumption... or have I got this all totally wrong??? Cheers Chantal

Hi Guys, Thanks for your quick response. SO in answer to your queries. ProDave, my manifolds aren't easy to access, but i can tell you that they are straight tubes in and out with the floor pipes attached,there are absolutely no valves dials or controls except the flow rate ones, so I can't tell what the temp is at the input and output stages. I am on bottled gas ? PeterW, no idea who installed it... but the buffer is direct plumbed to the boiler and has a coil inside. it is a closed circuit between the two. JohnMo - 60% water being added to it probably shows my ignorance here... I meant pushed through from the boiler to the coil to heat the water up, sorry! I also think the pump to UFH is more powerful than the pump in the boiler.. Hope these help... So in this scenario would a mixer value help in the mix... perhaps removing the buffer, adding a mixer value, have the boiler running at the optimum which I believe is 56 degrees with a mixer value keeping the water temp through the UFH at a constant 40 degrees? If the buffer tank wont ever get to temp because it is being drained by the UFH pump, the boiler is going to be running constantly hence the gas consumption... or have I got this all totally wrong??? Cheers Chantal

Desperate Advice Required!. My current set up is: 1. A 24w combi condensing boiler 2. 150Lts buffer tank. 3.Google Nest Thermostat The UFH pump is connected direct to the buffer tank, and the controller in the tank is linked to the pump and is set to only pump water around the system when the water in the tank is at 40 degrees. The boiler itself, when heating is being called by the Nest is set to 60 degrees. There is no mixer value installed currently. Firstly, is this a correct set up? Secondly the problem is, this set up means that the boiler is continually running and our gas consumption is huge, approximately 35 kgs over 3 days; and also, when the temperatures outside at 1/2 degrees or lower, the system really struggles to heat the house up to 20.5 degrees. The tank never seems to heat to more than 45 degrees despite 60% water being added to it, unless the UFH is switched off completely. Can someone please explain the need for the buffer tank and whether it is better to have this than have the UFH connected direct to the boiler, which can then be set at 40 degrees for the UFH. Also do I need a mixer valve fitted in the system somewhere? I look forward to any advice. Thank you.... Chantal, a complete beginner when it comes to UFH systems!