Radiators with no TRVs - In series, or parallel?

condord

Hello,

I live in a house built in 2019. It has air to water heatpump. There are 2 thermostats in the house, in the main hall downstairs (Downstairs zone) and in the upstairs master bedroom (upstairs zone). In each of these areas with the thermostats, the radiators have no TRVs. I have read this is expected, as it is standard practise to ensure all radiators are not closed off causing undue pressure on the heatpump if there is no circuit open.

My question is, are these 2 radiators with no TRVS connected in series with the other radiators in the zone, or in parallel?

For reasons I won't bore you with, I want to reduce flow in the master bedroom by tightening the valves and want to make sure flow to the other radiators in the upstairs zone won't be restricted by that. If I do that, I will be removing the TRV head from another radiator to make sure 1 radiator upstairs always has full flow.

Thanks,

Cd

Wearb

If I understand you question correctly, they're connected in parallel.

You'll be upsetting the benefits of the thermostat and not allowing it to do its job.

Doing what you suggest would mean that that bedroom thermostat would never -or very slowly- reach temperature. Therfore continuously calling for heat.

Can you not just turn down that thermostat to achieve what you want.

Perhaps you'll need "to bore" us for us the have an accurate understanding of exactly what you're trying to achieve.

condord

https://www.boards.ie/discussion/comment/122704388#Comment_122704388

Thanks for your response. Here are the details:

The thermostats are connected to mechanical valves controlling water flow to the radiators upstairs and downstairs. When either thermostat calls for heat, the appropriate valve opens and the heatpump begins to pump water.

I have installed a second smart thermostat in another area upstairs that can also call for heat. The reason being that our bedroom heats faster because it is a small space, and I want to use the external stat, placed in another area, to decide whether to call for heat or not.

What I propose doing is removing the TRV control head from the radiator in the area with the new external stat. This will ensure it always has full flow. Then, I want to reduce the water flow to the radiator in our bedroom so that our bedroom doesn't heat as quickly as the other areas upstairs. This way, during the night, hopefully our bedroom will stay relatively cool compared to the area upstairs I want to heat. This will require no plumbing or replacing of valves, so seems to be an easy solution to our problem.

Wearb

Yes, just throttle the lockshield on the master bedroom back bit by bit until you achieve the desired result. You could fit a trv to it instead.

You can then turn that thermostat off and let the new one control the upstairs heat. I'm assuming the new stat controls the same valve as the existing one.

Lenar3556

I very much concur with the suggestions above.

The most practical solution here is to balance the radiators so that the required heat is delivered to each room. It should be possible to achieve most of your objectives through a combination of balancing and correctly set stat temperature. Adding a second stat to the same heating circuit is complicating things.

It will take some trial and error, but you’ll get there. If you don’t already have, perhaps also consider a fully programmable stat (different temps can be programmed for different times of the day). Heatmiser Neo as an example - but there are several options.