Going green(er) with a Viessmann 200W (& heating efficiency home improvements)

Screwdriva

Reed_Richards said:

It looks like you would need the Vitrotrol 300A to give you control over your upstairs and downstairs zones and the ability to program and control your hot water.  Any other controller and you might be in difficulty because:

I believe the 200-W now supports Opentherm since that review was written but yes, we'll need either a Nest or their own thermostats.

Reed_Richards

Plenty of other Opentherm options apart from Nest.

Reed_Richards

Screwdriva said:
... the installer asked if we would be willing to consider a Vaillant Aerotherm Air Source Heat Pump. Next steps are a heat loss assessment to determine if the heat pump will actually save us enough £ to pay for the £3-4K extra we'd need to pay upfront. 

Has this happened yet @Screwdriva ?  You'll benefit because this will also give you a much clearer idea of whether your radiators, relocated upstairs, will be big enough to do the job if you go with your preferred option of a low temperature gas boiler.

Screwdriva

We've skipped this due to the lack of supply of Vaillant Aerotherm air source pumps for 12 weeks + incremental cost increase of £6K (heat pump, hot water tank at a minimum), which we would never recover over the life of the pump, even assuming a SCOP of 4.

In a way, I believe its for the best. I have a small garden and the house is surrounded by water. I'm hoping for a water/ ground source solution in the future which a higher SCOP.

Just laid the Dunlop LX-40 self leveling compound yesterday. The 4 groove 25mm XPS UFH boards will be glued onto this next followed by installation of the Polypipe kit. Then comes the Viessmann 200-W boiler and tiling. 

Still doing some research on what we should use for tile leveler. Dunlop LX 360 Fibre appears to have good reviews and is designed for UFH. Not sure why but has something to do with the lack of organic protein and fibre?

Will be sure to update this thread as the job progresses. 

Reed_Richards

I just had a small tiled floor laid for me that came out wonky despite being on top of self-levelling compound.  The tiler had some little plastic gadgets for aligning the edges of adjacent tiles but it was late in the day and they were so busy concentrating on the trees of these gadgets that they lost sight of the wood of whether the floor was overall level.  My conclusion is that self-levelling compound is unnecessary under a tiled floor unless it is grossly bad because you can still compensate (or mess it up) with uneven thicknesses of tile adhesive.

Self-levelling compound is expensive!  Don't bother with it unless you really have to.       

Screwdriva

Reed_Richards said:

Self-levelling compound is expensive!  Don't bother with it unless you really have to.       

Our concrete had craters in it and the floor was very uneven. It's still uneven after the LX-40 SLC! I suppose you could argue that our plan to pour fibre LX-360 over the piping/ UFH boards, prior to using the S1 adhesive, is overkill. Here's a video with ol' Roger explaining why.

https://www.youtube.com/watch?v=sROYvfYV3B4

Screwdriva

A few updates:

1. We're filming an episode for the Urban Plumber's YouTube channel next Monday when we lay down the remainder of the UFH boards using flexible adhesive.

2. We have decided not to install any thermostats with the Viessmann 200-w. Advanced weather compensation will effectively autopilot once commissioned with override will via Smart phone if needed. Some £ saved. 

3. Once the piping is installed, the LX-360 compound will be poured over it, followed by S1 tile adhesive mixed with an S2 additive for maximum flexibility.

Reed_Richards

Sure, surely, a water source heat pump is what you should be getting?

QrizB

Reed_Richards said:

Sure, surely, a water source heat pump is what you should be getting?

That has been discussed previously

michaels

Screwdriva said:

A few updates:

1. We're filming an episode for the Urban Plumber's YouTube channel next Monday when we lay down the remainder of the UFH boards using flexible adhesive.

2. We have decided not to install any thermostats with the Viessmann 200-w. Advanced weather compensation will effectively autopilot once commissioned with override will via Smart phone if needed. Some £ saved. 

3. Once the piping is installed, the LX-360 compound will be poured over it, followed by S1 tile adhesive mixed with an S2 additive for maximum flexibility.

Our 10yo 200-w with weather comp gets it wrong with solar gain (too warm) and wind load (too cold) - being older the only override is on the boiler itself.