New House, brand new system, weird goings on.

[peatoire]

Hello people, I have a pressurised system with hot water tank and a Viessman boiler.I have 2 zones: Downstairs and Upstairs, both controlled by separate room thermostats.

Through basic investigation I've realised that there are two rads upstairs that are on the same 'plumbing' (forgive my terminology) as the downstairs rads.
They are in the upstairs hall where the room thermostat is located so not only am I getting a natural flow of heat traveling up through the landing, I'm also getting heat from the rads which are on the same line as the downstairs rads.

My problem is this, all the bedrooms stay cold as the thermostat gets up to temp before the bedroom rads barely come on, so I think to myself 'turn up the upstairs thermostat to compensate', all well and good until the bedrooms reach temp and then they get hotter and hotter because if doors are closed all the heat is trapped in the bedrooms.

So I'm thinking someone's cocked up the plumbing install until I go next door and their house is the same, builder says it's necessary to have at least one upstairs rad controlled by the downstairs thermostat. I reckon he's talking rubbish but need someone to set me straight if not.
Surely if all upstairs rads where controlled by the upstairs thermostat I wouldn't have to leave all the doors open to stop overheating as the entire 1st floor would heat up uniformly if balanced correctly.

Soz if I've overcomplicated this but in short:
1st floor thermostat not getting an accurate representation of the 1st floor temp because adversely affected by incorrectly plumbed nearby rads.
Any help appreciated
Andy

 

[Mr Smyth]

Without seeing your house layout it is difficult to comment.

I often see this. Attempts to zone the house that just fail. In one case a 3 storey house with a large open central staircase with the 3 stats on the on the landing of each floor. Effectively all in the same room and just 2.5m apart!

Some suggestions?
1. Increase the temp of the upstairs stat to effectively balance the house?

2. Relocate the upstairs room stat into say the master bedroom?

3. Put TRV's on the bedroom rads?

A combination of 1 and 3 might be best.

Hope this helps

 

[picasso]

your absolutely right , there should not be any connection between the two zones, a common problem is the hot water return connected in the wrong place, which makes some radiators heat up when they shouldent, try turning off the hot water and see if the rads upstairs still heat up.

 

[ducatikid]

OP as the previous poster said , its difficult to say absolutely without seeing the system , however another short term solution would be to turn off the closest radiator to the upstairs stat or maybe even both (you said you have two radiators in upstairs hallway). This will at least give the upstairs zone a chance to come on and heat effectively. Bottom line is , it sounds wrong , you don't have to have a radiator upstairs running off a downstairs zone. Good luck!

 

[peatoire]

Thanks for all the prompt replies.
I think I'll get the developer to sort it if it's not right. All rads have trv's but I use those to balance the flow rate. I originally thought it was only the one rad near the room thermostat and so turned it off which did improve things, but it is on my mind that it could be a lot better if plumbed properly, appreciate everyone's input. I do use two Drayton +3 programmable therms so I might see about an RF version to put in the bedroom if it's too big a job. All plumbing is flexi pipe but I don't want all my carpets and floorboards up.