auto bypass valve

[gas4you]

Whilst latest regs stipulate an auto bypass valve to be fitted, especially on an 'S' plan, your aged Classic does not actually need one. It does not have any pump overrun built in as it is only supplied with a single switched live.

By all means fit one if you want to it is good practice.

The above assumes you are correct in stating you have an Ideal Classic.

 

[jep49]

bamber why will it just keep circulating round. isnt that the idea of the auto valve to prevent that

 

[jep49]

gas4u thanks for a sensible reply i will put one in anyway. in your opinion do you think its enough to connect to the 15mm on tank return. ait definately has no pump overrun, and i will check the boiler model before i do anything

 

[gas4you]

In your particular case I can forsee no problems with connecting to the cylinder return, AFTER any balancing valve in this pipe work.

15mm will be plenty enough, as I doubt that it will ever be used, except in a failure of the zone valves (stuck shut) and the actuator head microswitches sticking in the on position, thus firing the boiler and pump when there is no actual genuine call for heat.

 

[jep49]

thanks gas4u. why does it matter which side of the gatevalve i fit the auto valve? surely the balencing gate valve will remain partly open the same as present, and will be overridden by an auto valve possibly operating

 

[Bambergaspipe]

bamber why will it just keep circulating round. isnt that the idea of the auto valve to prevent that

Depends on wether an auto or gate valve is fitted, if gate valve on 22 left fully open it wont get to rads, with 15mm it still will.

 

[Bambergaspipe]

gas4u thanks for a sensible reply

Hope that reply was sensible enough for you.

 

[gas4you]

thanks gas4u. why does it matter which side of the gatevalve i fit the auto valve? surely the balencing gate valve will remain partly open the same as present, and will be overridden by an auto valve possibly operating

Tee it in on the boiler side of the balancing valve, so there is no further restriction, or chance of the gate valve being shut.

 

[jep49]

it is 15mm on tank return to i presume 22mm on the rad return under the floor. at present there is a gate valve in this pipe. this was fitted by a plumber a few years ago when the system clogged up due i think to the builders having put no additive into the new system. do you think i should just replace the gatevalve with an uutomatic bypass valve. these are mainly 22mm i think and will need reducers

 

[gas4you]

The auto bypass valve is totally different to this balancing valve. Keep them seperate.

 

[jep49]

bamber i am more enlightened by the minute

 

[jep49]

thanks gas 4u so keep the gatevalve . and i am ok with the 15mm . do you happen to know of any valves in 15mm

 

[jep49]

cant effin wait

 

[jep49]

If the auto bypass valve is closed most of the time when the trv are open, and then required to open to allow a possible flow through it, wont the gatevalve then cause a restriction to the new required flow.

 

[gas4you]

No because you are teeing it in on the boiler side of the gate valve.

Get a 22mm valve and reduce the pipes down. I don't know of a 15mm version personally.