Recent content by fezster

  1. F

    Vaillant heat only boiler + switched live thermostats + weather comp?

    You're trying to find a solution to a problem which shouldn't exist. Check your blending valve is working and is set correctly, or adjust if possible.
  2. F

    Vaillant heat only boiler + switched live thermostats + weather comp?

    Underfloor heating usually has its own blending valve to separate it's flow temps from the rest of the heating system.
  3. F

    VR65/VR66 for HW flow temp control

    I have an ecotec plus 438 boiler and I use the SL for both heating zones and DHW. If I remember correctly, for ebus to fire the boiler you needed to leave the boiler terminals 3+4 bridged (I dont have it bridged and the boiler only fires on the SL).
  4. F

    Vaillant heat only boiler + switched live thermostats + weather comp?

    D0 and D77 are configurable independently - the D77 kwh output will only be used when the boiler is instructed into DHW mode by the Vr65. The tap symbol on the front will show and the flow temperature will be boosted to 80 degrees (or whatever is set in D78) plus limited by the max temperature...
  5. F

    VR65/VR66 for HW flow temp control

    Exactly as @notorious said.
  6. F

    Vaillant ecoTEC 630, UFH, Heatmiser and VR66 for Cylinder Control

    I was part of those original threads and can confirm the VR66 works exactly as the VR65 does in mono mode. Although given the post above from scw, it seems your boiler may not require the VR65/66 to boost flow temps for HW. Whichever method you choose, you will need to clamp your CH temperature...
  7. F

    Vaillant heat only boiler + switched live thermostats + weather comp?

    I have a very similar setup to notorious, except I'm using a vrc 470f with wireless outside sensor, using a VR66. I have 2 heating zones so wired my CH zone valves via a 2 pole NC contactor (about 10 quid) which is activated when nest calls for HW (and shuts the CH zone valves). I found...
  8. F

    Domestic Property 1000 Litre Cold Water Pressure Tank

    An accumulator will provide roughly 50% capacity, depending on pre-charge and incoming mains pressure. So you'll have roughly 500L of usable capacity.
  9. F

    Vaillant Ecotec Plus 418 - Heating Issues (Constant Anti Cycling?)

    Great post @ScottishGasMan. I'd add to what you said about the benefit of a LLH in that you have a primary and secondary pump. The primary shunt pump only has to overcome the head required for the boiler (which in the 438s case is considerable). This means smaller domestic pumps can be used...
  10. F

    Lead to mdpe pipe worth it?

    You need to take some measurements with a pressure guage and a weir gauge (or a calibrated bucket with stopwatch). Measure your static pressure and then measure the dynamic pressure with an open tap, whilst also measuring the flow rate. If you are getting a massive pressure drop, then upgrading...
  11. F

    S-plan plus: second zone depends on first?

    Most likely, the ST6400C programmer is being used for both u/s and d/s, but the zones themselves are being heated independently via the room thermostats. So you are still getting independent control, you just need to use the programmable thermostats to control timings, rather than the programmer...
  12. F

    Hardcore for new driveway

    You want 4-6 inches of type 1 for residential. If they have just added type 1 on top, Im not sure how they intend to get the levels correct.
  13. F

    Hardcore for new driveway

    It won't be a comfortable conversation, but I'd get them to stop now, before they do more work which you'll have to redo (or live with) in a few years time. It's your home, so you'll have to look at it for years to come, so even if you simply accept you may have to cut your losses on what's...
  14. F

    CH - Very small frustrating leak

    Appreciate the offer, nonetheless :)
  15. F

    CH - Very small frustrating leak

    I'm in SE London. Thanks for this suggestion. Even though, I had been regularly checking the TRV's - very time consuming with 30+ radiators, it does look like one of them was still weeping a small amount of water occasionally. It does seem to be only during cool down this happens and not every...
Back
Top