Tado / Bypass Radiator

[gjw123]

Hi All

I've just bought some Tado smart radiator thermostats (awaiting delivery).

I've checked all the radiators and they're all TRV's (including towel radiator), expect one, which has two manual valves. I am assuming this is perhaps a bypass radiator, however, my impression was generally these were fixed valves with two lockshields that you couldn't turn off, which isn't the case with this one, as you can.

The issue is, this is the main and large vertical radiator for the living room, therefore, ideally this is one I'd want a Tado Smart Radiator Thermoatat on.

1). Would I be right in thinking that if I wanted one on here, I'd need to switch one of the other radiators (in a less important area) to a manual valve to act as the bypass radiator?

2). Does bypass radiator have to be completely open / on the max heat setting, or could I turn it down low, to save costs if it does have to act as the bypass?

3). I don't know if I have a bypass valve, unfortunately. The boiler is a conventional boiler (Potterton 50EL), therefore, I can't imagine it has one built in like many modern combi ones do. I've checked by the fortic tank and can see what appears to be a gate valve. I'm not sure if this can act as a crude version of a bypass.

I've attached pictures of the gate valve and the manual valve radiator.

Any advice would be much appreciated this!

 

[mcprinter]

DIYer

I have Wiser. Same sort of system as Tado. 30 odd year old Ideal system boiler.
My towel rad is the bypass on manuals. Towels always dry.

Your system shouldn't run on too long if all the Tado TRVs are satisfied.
I believe the idea of the bypass is so the pumped CH water has somewhere to flow in the event that all TRVs are shut when the boiler and pump are running.

On the rad you select as the bypass you could just fully open the dumb TRV (or even remove the head to prevent others fiddling) and adjust the flow through the rad via the lockshield.
Since you will have to drain to fit TRV to the lounge rad, might be better to change to manuals.

Also have a fortic tank. That is for your hot water and won't be part of your CH circuit.
I am presuming you have a 3 port valve. Or 2 2 ports for HW/CH? And that the HW/CH are controlled independently.

 

[BlueLoo]

Open to correction but....

You do seem to have a manual bypass (red gate valve) and an old constant speed pump.

Therefore you don't need any rads to be locked open and can fit TRVs on all of them.

Yours was how my system was before i went down the CH rabbit hole.

Because you have a manual bypass and a CS pump, you could fit a ABV on the elbow. Which would improve things a little (better boiler performance etc).

If you ever change the pump. You'll have to do a few adjustments to take advantage of the PP mode energy savings.
Which would be going back to the manual valve bypass and adding a tacosetter device (flow meter) after it.

But for now you are ok.
You need to have the bypass open just enough to satisfy boiler flow through. It's a gate valve though and are ****e for setting flow. Perhaps open it up by 1/2 turn and see how you go.
The best way would be probably to fit the tacosetter inline with it but if you are not diy competant just do what plumbers do and guess (or leave it as it is!)

 

[gjw123]

.

 

[gjw123]

DIYer

I have Wiser. Same sort of system as Tado. 30 odd year old Ideal system boiler.
My towel rad is the bypass on manuals. Towels always dry.

Your system shouldn't run on too long if all the Tado TRVs are satisfied.
I believe the idea of the bypass is so the pumped CH water has somewhere to flow in the event that all TRVs are shut when the boiler and pump are running.

On the rad you select as the bypass you could just fully open the dumb TRV (or even remove the head to prevent others fiddling) and adjust the flow through the rad via the lockshield.
Since you will have to drain to fit TRV to the lounge rad, might be better to change to manuals.

Also have a fortic tank. That is for your hot water and won't be part of your CH circuit.
I am presuming you have a 3 port valve. Or 2 2 ports for HW/CH? And that the HW/CH are controlled independently.

Thanks for the reply.

I believe that the HW/CH are controlled independently.

Do you know how I would tell / where I would need to look to see if I do have an automatic bypass valve in the piping network? I had assumed it would be in the area I took the picture of (which is next to the fortic tank). If I don't have one, do you happen to know if it would be a particularly difficult job to install one?

In terms of the bypass radiator, do you mind expanding on what you mean by adjusting the flow through the rad via the lockshield? So if, for example, I were to choose the bathroom, I would fully open the TRV (or put it on max so to speak) and then adjust the flow through it via the other valve?

Or if I were to change it to a manual valve, would it need to be put onto max? This just seems quite a waste, given that I'm doing this to only heat individual rooms to a specified level to save energy. Could I put it on max, but restrict the amount through the other valve?

Also, regarding changing the valve body on the living room radiator from manual to TRV (so I can fit the Tado), would this be a case of simply switching over the valve connection on the flow side?

Thanks!

 

[gjw123]

Open to correction but....

You do seem to have a manual bypass (red gate valve) and an old constant speed pump.

Therefore you don't need any rads to be locked open and can fit TRVs on all of them.

Yours was how my system was before i went down the CH rabbit hole.

Because you have a manual bypass and a CS pump, you could fit a ABV on the elbow. Which would improve things a little (better boiler performance etc).

If you ever change the pump. You'll have to do a few adjustments to take advantage of the PP mode energy savings.
Which would be going back to the manual valve bypass and adding a tacosetter device (flow meter) after it.

But for now you are ok.
You need to have the bypass open just enough to satisfy boiler flow through. It's a gate valve though and are ****e for setting flow. Perhaps open it up by 1/2 turn and see how you go.
The best way would be probably to fit the tacosetter inline with it but if you are not diy competant just do what plumbers do and guess (or leave it as it is!)

Thanks for this - I had seen some videos in which people had left the gate valve open a half turn to satisfy the boiler and was hoping that this might be the case here.

Looking at the manuals left by this area, it appears I have a Honeywell V4073A Motorised Mid-Position Valve. By the boiler in the kitchen, there was a manual for a ZV range 2-port spring return motorised zone valve with an auxiliary switch.

I suppose my only issue now is working out whether it is open enough... it seems rather stiff! I'm assuming the way round this is to simply loosen it enough, totally tighten it, then untighten it a half turn...?

But essentially, should the valve be in the correct position, I can put TRV's on all valves in the house without needing to worry about a bypass, and that getting an automatic bypass valve isn't needed per se, but would be good to have generally?

 

[BlueLoo]

Thanks for this - I had seen some videos in which people had left the gate valve open a half turn to satisfy the boiler and was hoping that this might be the case here.

Looking at the manuals left by this area, it appears I have a Honeywell V4073A Motorised Mid-Position Valve. By the boiler in the kitchen, there was a manual for a ZV range 2-port spring return motorised zone valve with an auxiliary switch.

I suppose my only issue now is working out whether it is open enough... it seems rather stiff! I'm assuming the way round this is to simply loosen it enough, totally tighten it, then untighten it a half turn...?

But essentially, should the valve be in the correct position, I can put TRV's on all valves in the house without needing to worry about a bypass, and that getting an automatic bypass valve isn't needed per se, but would be good to have generally?

Yea, correct.

If the bypass isn't open enough, the boiler will trip. Just open it a little more, reset the boiler and so on and so forth.

 

[mcprinter]

Only a DIYer
The 'other valve' is the lockshield
Opening the TRV fully will make sure it doesn't close and stop flow.

If you have a look at balancing, it will probably explain the flow better.

Silly analogy
Conveyor belt with sushi
Wide open lockshield and that rad will eat almost every piece until full (TRV closes and no flow through that rad)
The next rad will get the odd piece. Then get more once Rad 1 is full.
The rad after that gets even less, etc.
Adjusting the lockshields correctly (balancing) will ensure every rad gets their fair share.

 

[BlueLoo]

Only a DIYer
The 'other valve' is the lockshield
Opening the TRV fully will make sure it doesn't close and stop flow.

If you have a look at balancing, it will probably explain the flow better.

Silly analogy
Conveyor belt with sushi
Wide open lockshield and that rad will eat almost every piece until full (TRV closes and no flow through that rad)
The next rad will get the odd piece. Then get more once Rad 1 is full.
The rad after that gets even less, etc.
Adjusting the lockshields correctly (balancing) will ensure every rad gets their fair share.

Yeh, hmm.

I'm only a DIYer as well but.

Read my post history for opinion on "Balancing".

I see no value in reducing the performance of the system unless you have a problem. Especially so where all or most valves have TRVs.

(Unless you have a crap install and then you are modifying the hydraulics to problem solve)

Imho, just open everything up and let the trvs do the work. Unless you have particular problem rads.

Works great for me. (And other plumbers here as well).

 

[denso13]

I'd need to switch one of the other radiators (in a less important area) to a manual valve to act as the bypass radiator?

Don't fit a TRV in the room with the wall thermostat.

 

[BlueLoo]

Don't fit a TRV in the room with the wall thermostat.

Hmm.

Not true for (some) modern controls.

Wiser system simply gives control over to the wireless thermostat paired to the trv.

Dunno about Tado though. Op should check.

 

[Mister Banks]

Personally I wouldn’t have a smart TRV in a bathroom. I’m sure it has been done but I don’t think the moisture levels and all that talc powder dust being good for the electronics.

 

[Mister Banks]

Yeh, hmm.

I'm only a DIYer as well but.

Read my post history for opinion on "Balancing".

I see no value in reducing the performance of the system unless you have a problem. Especially so where all or most valves have TRVs.

(Unless you have a crap install and then you are modifying the hydraulics to problem solve)

Imho, just open everything up and let the trvs do the work. Unless you have particular problem rads.

Works great for me. (And other plumbers here as well).

It’s a minefield concerning balancing, zoning and the effect on heating and boiler efficiency.

 

[BlueLoo]

It’s a minefield concerning balancing, zoning and the effect on heating and boiler efficiency.

I know.

I'm doing a lot of research to get clarity on this because my old non condensing boiler which doesn't really care about return temps, etc is getting long in the tooth.

No official or advisory groups mention it though.

I get that those doing this for decades may be thinking wtf at the idea of not doing it but i am coming at it from the other side.

Why do it at all?

Not really had many structured answers so far.

 

[BlueLoo]

Personally I wouldn’t have a smart TRV in a bathroom. I’m sure it has been done but I don’t think the moisture levels and all that talc powder dust being good for the electronics.

Best place for one.

Give it a twist when you are having a shower or bath and you get the room dryer much quicker, a warmer bathroom and a warm towel

Reliability hasn't been an issue for mine at all.