A
ALEC1
yes that may well have been another solution, but towel rail circuits can be very wasteful on hot water .......and yes the towel rails are weather compensated, but on a much higher curve than the floor...
Weather Compensation on Both Rads and UFH?
- Thread starter GeorgeWBush
- Start date
- Status
Sponsored Links
So if you use the VR61 and have rads on HK1 and UFH on HK2 then hot water, you've ran out of circuits and won't be able to give the towel heaters their own. Shame because they'll be on/off all the time when the cylinder satisfies.
Might be worth looking at the Veissmann products, the Vaillant stuff seems a bit limited.
Might be worth looking at the Veissmann products, the Vaillant stuff seems a bit limited.
A
ALEC1
i would love to know how they do towel rails in germany... on the cylinder I guess, or even the cylinder primaries....
Do you mean pipe them off the cylinder via a secondary pump?! As in mains water? Or off the coil?
Just googled it, didn't realise you could even do it with a secondary pump! Useful, but I imagine it can be very wasteful.
Also, If using hot water priority could it mean the heating is off for too long? Lagging the pipework would be essential!
Just googled it, didn't realise you could even do it with a secondary pump! Useful, but I imagine it can be very wasteful.
Also, If using hot water priority could it mean the heating is off for too long? Lagging the pipework would be essential!
Sponsored Links
So is lagging the towel rail to comply with the Water Regulations.
When I started working for a living, the NHS was busy ripping out all the pipe coils heated by the HWS secondary systems, after the recent discovery of legionnaires' disease. That was a long time ago.
With a potential readership here of 1100 it would save a lot of call answering to just post it on here.
I have a nifty way as well. I just connect it directly to the boiler so its heated all the time the boiler is on.
Those who connect it to the cylinder coil find it comes on AFTER someone has a bath which is not much use. Its only on for 20 min while the cylinder reheats.
Tony
Which often turns out nicely to be the time you want toasty towel?
A
ALEC1
but tony how would you connect it to a four pipe boiler? thats the question?
Just spoke to Viessmann technical and asked what options were available to me.
The guy explained that I could go for constant temperature or WC.
Constant Temp
Programmable room thermostat and 2 port mixing valve for each zone (no $hit Sherlock I hear you say?)
So I would need 4 lots of these and he estimated this could probably be done for under £1000.
or
Weather Compensation on the boiler
I would have to combine the 2 radiator zones into 1.
I could have 2 sep ufh zones.
I would need 1 divicon (without mixer, appx £500) for the 1 central heating zone
I would need 1 divicon (with a mixer, appx £1000) for each of the UFH zones (so 2 lots of these).
This makes a total of £2500 exc the boiler! On top of this I would of course need the UFH kit, and all the other bits and pieces (pumps, valves etc).
With Vaillant not recommending WC setup with UFH and the Viessman WC option being too expensive for me I think I'll have to forget the WC and just go with a normal thermostat setup.
The guy explained that I could go for constant temperature or WC.
Constant Temp
Programmable room thermostat and 2 port mixing valve for each zone (no $hit Sherlock I hear you say?)
So I would need 4 lots of these and he estimated this could probably be done for under £1000.
or
Weather Compensation on the boiler
I would have to combine the 2 radiator zones into 1.
I could have 2 sep ufh zones.
I would need 1 divicon (without mixer, appx £500) for the 1 central heating zone
I would need 1 divicon (with a mixer, appx £1000) for each of the UFH zones (so 2 lots of these).
This makes a total of £2500 exc the boiler! On top of this I would of course need the UFH kit, and all the other bits and pieces (pumps, valves etc).
With Vaillant not recommending WC setup with UFH and the Viessman WC option being too expensive for me I think I'll have to forget the WC and just go with a normal thermostat setup.
I thought I'd be able to save gas as I could more finely control heating in the house.
With regards to zoning the UFH, I wanted the kitchen floor heating to be seperate from the living room as it can get very hot in the kitchen at times without any heating at all (I mean just from the cooking).
Have a look at Honeywell's Evohome wireless system, which can be configured for mixed rad and UF systems with up to eight zones.
More details in the Application Manual and the Installation Manual.
More details in the Application Manual and the Installation Manual.
A
ALEC1
this is why I ask about zoning......is it a palace you live in?
if all of the house is regularly used there is no point in zoning....
run the guest bedrooms at lower temperatures on TRVs..
The real issue with zoning is that if you size a boiler for the whole house, and then only run two or three radiators at any one time you will seriously compromise reliability and efficiency...
In addition unless zones are thermally isolated it is pointless to have a heating system that is zoned.
If you drop the zones and do it the viessmann way you only need a boiler for the unmixed circuit and a brass bodied mixing valve with actuator that comes to about £400 plus the boiler..
It is "nuts" to turn on and off UFH heating, much better to temperature profile the flow.
if all of the house is regularly used there is no point in zoning....
run the guest bedrooms at lower temperatures on TRVs..
The real issue with zoning is that if you size a boiler for the whole house, and then only run two or three radiators at any one time you will seriously compromise reliability and efficiency...
In addition unless zones are thermally isolated it is pointless to have a heating system that is zoned.
If you drop the zones and do it the viessmann way you only need a boiler for the unmixed circuit and a brass bodied mixing valve with actuator that comes to about £400 plus the boiler..
It is "nuts" to turn on and off UFH heating, much better to temperature profile the flow.
A
ALEC1
Evohome has an opentherm bridge that matches the boiler output to the zone demand... the trouble is to use opentherm you need a special widget to convert the OT signal to ebus or KM bus... not generally available in the UK
M
mysteryman
Largely correct about the brass bodied mixer. However, the Sub mounting kit does the same job at much the same price, because you don't then need the separate pump. You also don't need the underfloor manufacturer's blending valve and you feed straight out to the manifolds. The Sub mounting kit is also plug-and-play, the only 240 volt to be wired is the main boiler feed from the fused spur. That's all you need, the timing and temp control is all in the weather comp controller. You don't need a sparky.
The diverter valve in these boilers is on the right, on the return connections. You can feed a heated towel rail by a tee from the dhw cylinder primaries. You take the return from the towel rail into the branch of a tee. Go from both ends of the tee through non-return valves connecting one into the dhw return, and the other into the radiator return. The HTR will be heated whenever the boiler fires, to full flow temp during DHW production, and at weather comp temp in CH. Thus, steady heat in winter, just a burst of heat in summer. No extra timers or motorised valves.
The diverter valve in these boilers is on the right, on the return connections. You can feed a heated towel rail by a tee from the dhw cylinder primaries. You take the return from the towel rail into the branch of a tee. Go from both ends of the tee through non-return valves connecting one into the dhw return, and the other into the radiator return. The HTR will be heated whenever the boiler fires, to full flow temp during DHW production, and at weather comp temp in CH. Thus, steady heat in winter, just a burst of heat in summer. No extra timers or motorised valves.
Compared to some of the rented dumps down our road it is yes.
It is my home yes, and it is lived in all day.
Can I confirm I've understood, you're saying If I forget all the zoning then the brass bodied mixing valve with actuator would allow me to have WC without having to buy any more Viessman devices (i.e. the divicon devices)?
I could live without the zoning of the raditors, but not the UFH, as I would need to be able to control the kitchen UFH independantly from the Living Room. Do you know if there is a way Alec to have the 2 UFH zones using Viessman products without having to buy the (extortionate) divicon devices?
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
- Status
Sponsored Links
