If display is 55 degrees on vaillant boiler is that when boiler is at most efficient?

[Harry Bloomfield]

Interesting. I got a 627 system boiler. Vsmart and a vaillant unistor. I have 14 rads a big 5 bed house. 1960s home. Large windows. Cavity with retro fitted insulation. I am using 26000kwh a year on gas. I do use have a gas job but that’s it. I still expect a bit better.

9x rads, Econofit 418, with outdoor temperature sensor - rest of the system is 40 years old, in a semi, gas hob, double gas oven. DG, CWI and I uses 10130Kw over the past year.

As I mentioned earlier, I am experimenting with gas consumption for this winter, making more use of the previously unused living room gas fire.

Vsmart however always get tempreture set very well with little or no spikes.

Same here and I constantly record my indoor/outdoor temperatures. It has never over shot - it just throttles down perfectly, then just maintains the temperature silently.

 

[vulcancontinental]

I wonder if there might be any value in automating the flow and return temperatures and in some way throttling the circulation through the boiler and system, to optimise it?

Vokera Unica Max and I believe an Ariston model have the option of a ∆T setting for the pump to main a target across the heat exchanger.

 

[Johntheo5]

That sounds great but how could any form of steady room temperature control be achieved with this while using TRVs, smart or otherwise? all TRVs work/contol by changing the dT across the radiator and when the rad demand is satisfied and steady the boiler will produce exactly enough power to give the exact same dT across the boiler Hx?, as the flow through the rad and boiler will be exactly the same, if the ambient conditions rise then the TRV's will throttle in resulting in a higher dT, to give the reduced rad output and the boiler will follow suit. But if one takes measures to maintain a constant boiler Hx dT then what happens??.

 

[mrbg07546]

I had a look this morning ina. Real life heating scenario. It was 51 flow and 33 return. That looks much better!

 

[mrbg07546]

The loft takes longer to get up to tempreture but I’m gonna bleed then rads and it will probably be ok

 

[Johntheo5]

I had a look this morning ina. Real life heating scenario. It was 51 flow and 33 return. That looks much better!

That's excellent, gives > 97% boiler efficiency.

The loft takes longer to get up to tempreture but I’m gonna bleed then rads and it will probably be ok

Pump on speed 1?.

 

[mrbg07546]

That's excellent, gives > 97% boiler efficiency.

Pump on speed 1?.

Yea should be fine. It did heat up ableist a bit slower. But might just keep the pump at 1

 

[mrbg07546]

I’m noticing dips in electricity usage by around 75% according to vsmart. Any ideas why? That’s bigger then I thought!

 

[mrbg07546]

I did test the electricity usage . The smart meter was whining 14.2kwh vs 19 on the vsmart. We didn’t use the gas hob. (Our only other gas appliance) . A large estimation?

 

[mrbg07546]

I tested the vsmart energy usage again. It says 8kwh gas but my smart meter shows 11ish. I think it’s a estimate based on the amount of time heating is on. It does t consider target flow tempreture which in this weather(which is very cold) the boiler has decided to set it on low.

 

[Harry Bloomfield]

It says 8kwh gas but my smart meter shows 11ish.

A smart meter's reports might be an average over a much longer period of time. My IHD takes quite a long time before it shows a true reading, way behind the boilers actual consumption.

 

[mrbg07546]

interesting the vsmart doesn’t give much information about boiler at all. But the myvuabt pro app only advance engineers can install shows a lot more info

 

[mrbg07546]

Just as a update I actually set d.00 to 9kw and set pump speed back to auto (rather then 1.53%) I seen it was setting pump to 15%