Can I used wireless for a pump overrun cable?

[John2016]

I am having an Intergas HRE OV 18 installed, however, noticed I need a permanent live (pump over run cable), at present I only have a three core cable which has a switched live, neutral and a earth.

I heard someone mention about using a wireless RF module which would work instead of running additional cable which is a huge task.

Is this possible?

 

[Harry Bloomfield]

Is this possible?

Possible, but not as reliable as a properly wired system. Much better is you find some way to add the boiler to pump cable.

 

[stem]

An RF switch can only switch what is already there. So, as you only have a switched live it can't generate a permanent live from it.

I'm not familiar with your particular boiler, but I think that it's likely that a permanent live will also be required for the fascia mounted controls.

I have used as a temporary measure an RF switch connected to the pump overrun output from the boiler that sends a signal to a remote pump to control it, but that's generating a switched live from an existing permanent live, not the other way around.

You could repurpose the switched live as a permanent live and then send the switched live via an RF switch, but really a new connection is by far the best way to go, but it should come from the same fused connection that supplies the rest of the heating system so that everything is isolated together.

 

[ianmcd]

I heard someone mention about using a wireless RF module which would work instead of running additional cable which is a huge task.

Are you sure the werent talking about the intergas HRE eco RF Boiler ? it has an inbuilt RF receiver so if you had a combi and not a system boiler then only a permanent live is required, but wont work on a system boiler

 

[John2016]

An RF switch can only switch what is already there. So, as you only have a switched live it can't generate a permanent live from it.

I'm not familiar with your particular boiler, but I think that it's likely that a permanent live will also be required for the fascia mounted controls.

I have used as a temporary measure an RF switch connected to the pump overrun output from the boiler that sends a signal to a remote pump to control it, but that's generating a switched live from an existing permanent live, not the other way around.

You could repurpose the switched live as a permanent live and then send the switched live via an RF switch, but really a new connection is by far the best way to go, but it should come from the same fused connection that supplies the rest of the heating system so that everything is isolated together.

So I am thinking of repurposing the earth cable as a switched live and re-sleeve the earth cable. I have a cooker hood near by and use the earth cable from the hood to connect to the earth of the boiler.

However, the fused spur I have only for three wires, it is possible to have a switched spur for four wires?

 

[John2016]

Are you sure the werent talking about the intergas HRE eco RF Boiler ? it has an inbuilt RF receiver so if you had a combi and not a system boiler then only a permanent live is required, but wont work on a system boiler

I wish I could use the Eco, but I have a height restrictions

 

[muggles]

So I am thinking of repurposing the earth cable as a switched live and re-sleeve the earth cable. I have a cooker hood near by and use the earth cable from the hood to connect to the earth of the boiler.

No, definitely don't do that, it's absolutely against the terms of BS7671 Wiring Regulations

 

[stem]

However, the fused spur I have only for three wires, it is possible to have a switched spur for four wires?

Some heating systems require permanent lives for a programmer, two or more motorised valves and the boiler, so at least 4. Usually there's only one connection to the fused spur and the others are picked up from either a junction box or wiring centre.

Sometimes I've fitted a loose terminal inside the fused spur backbox to get an extra connection, one wire in & two out.

 

[John2016]

No, definitely don't do that, it's absolutely against the terms of BS7671 Wiring Regulations

Oh this was recommended by the manufacture. Isn't this the same as using a 3 core, the earth would be re-wired on both ends and re sleeved.

 

[John2016]

Some heating systems require permanent lives for a programmer, two or more motorised valves and the boiler, so at least 4. Usually there's only one connection to the fused spur and the others are picked up from either a junction box or wiring centre.

Sometimes I've fitted a loose terminal inside the fused spur backbox to get an extra connection, one wire in & two out.

Yep, that's what I need, a permanent live for the pump over run. It was just that I wanted to spur off the switched live as well as permanent live and neutral.

 

[muggles]

Oh this was recommended by the manufacture. Isn't this the same as using a 3 core, the earth would be re-wired on both ends and re sleeved.

Yes it is, and you're not allowed to do that any more either. 2nd Amendment to the 18th Edition specifically prohibits it

 

[John2016]

Yes it is, and you're not allowed to do that any more either. 2nd Amendment to the 18th Edition specifically prohibits it

Understood. Whats your view of using the Baxi 800 Heat Only instead of the Intergas, Baxi claim you don't need a pump over run?

 

[Harry Bloomfield]

So I am thinking of repurposing the earth cable as a switched live and re-sleeve the earth cable.

That is a really bad idea, and without doubt in contravention of the regs.. Do the job properly, please.

 

[muggles]

Understood. Whats your view of using the Baxi 800 Heat Only instead of the Intergas, Baxi claim you don't need a pump over run?

Eww no, awful boilers. Do you actually need 18kW, has a heat loss calculation been carried out on your property?

 

[John2016]

Eww no, awful boilers. Do you actually need 18kW, has a heat loss calculation been carried out on your property?

Nope, heat loss is 3 KW. But can't find a cost effective reliable boiler apart from Intergas....