Central Heating and Hot Water Questions

[AndrewCurren]

Good afternoon everyone.

I have just recently moved into a new home and in here there is what feels to me a complex heating system comprising of (I will try and list everything we have):

Veissmann Vodens 100-W Condensing boiler
Reliance underfloor heating manifold
Salus 7 day control that can control hot water and heating
Hot water tank (I believe to be unvented)
Heatmiser UH8-RF and Heatmiser NeoAir V2 thermostats (to control downstairs underfloor heating)
Hive for upstairs radiators
Neohub v2 for app connectivity

The issue I have is the underfloor heating seemed to be on today even though the thermostats were set to come on at a lower temperature than what it currently is, whislt I was trying to understand this I am also a little confused how the hot water works. I have set the Salus to On which I think is always on for the hot water but it doesn't seem to do anything by this I mean no activity, even if I turn up the thermostat on the boiler. I have checked the taps and there is very hot water coming through but I haven't seen (not been watching all day mind) the boiler come on to top up the hot water tank.

My question is if there any experts who would even know how to use this system know is it the Salus that would control the hot water or the Heatmiser thermostats?
Would I have to use a considerable amount of hot water to drain the tank some and then allow it to top up and the boiler to start up?
The temperature display on the boiler front, is this the hot water, heating or just the temperature of the water going through the boiler?
The NeoAir V2 thermostats come with a quick start guide for with a Mode 3 - Heating and Hot Water and a boost option for hot water, but this is only under the Hold option to override which I don't understand how these thermostats are able to control hot water as well as the underfloor heating.

It's all a bit complicated to me as I was used to a dual zone combi system prior with Hive on both zones so this baffles me a little.

Hope someone can help.

Thanks in advance

Andrew

 

[cross thread]

Regarding hot water ,have you checked if it has an immersion heater ? that may be on

 

[DP]

Need not be any thermostat or timer. Could be faulty MV that is calling for heat or not closing properly

 

[AndrewCurren]

@cross thread yes it has an immersion heater in the tank, this looks to be wired to a switch that is on all the time. I’m not well up on these, we had a British Gas service about 3-4 weeks ago who gave it all a good going over and said it was ok. Unless they didn’t check the tank side but would have thought they did as it’s all part of the heating system. Would an immersion heater only be a backup and not the sole heater for the boiler?

If we used some hot water would this top up straight away and therefore take demand from the boiler? We’ve had showers this evening and the boiler display is now showing 28° so hasn’t been on for a while.

 

[cross thread]

Yes the immersion would reheat the hot water if on permanent , expensive way to heat it.check your electric meter readings, to find out

 

[AndrewCurren]

If I turn off the immersion heater will the boiler then detect the temperature drop and kick in to heat up? But how will it heat all the water in the tank without running it all through the boiler and back in? Sorry if this sounds a bit noddy but I’ve no idea. I have got a plumber coming in September to look for me. My electric bill for one month is around £152 so think something is using it a lot

 

[cross thread]

Without seeing your system the gas boiler can operate the hot water heating via the cylinder and the radiators ,both can be set independently ,the gas boiler will operate when the clocks and thermostats are on.

 

[AndrewCurren]

Thanks, this is what I would have thought. The switch to the immersion heater is on so thinking this is on all the time but wonder if this being on and keeping the water hot is stopping the thermostat for the boiler kicking in.