Bypass radiator

[bhm1712]

what is the definition of a bypass radiator, and is it plumbed in differently than a usual rad? all i know is that it is there as a safeguard for the boiler so there is always a path of flow.

is it possible that on a system with no auto bypass and no rad with 2 lockshields or no valves at all that one of them is still a bypass radiator?

i have been reading that a bypass rad should be fully open either with 2 LSV or no valves at all. if thats the case how can you balance the system properly?

 

[doitall]

Perhaps By-pass radiators are outlawed under the efficiency regulations, unless its a heat sink.

 

[bhm1712]

i dont care whether they are outlawed....my whole house is outlawed now because its 20 years old. i just want to know how it should be setup and if its piped differently

 

[Gas2Air]

Don't be snappy. Most installations are in accordance with MI. For example a bypass of 6-8m is required on S-Plan. This in practice is difficult so a radiator is normally used. Depends what system you have.

 

[bhm1712]

c plan,

gravity hot water pumped heating

glow-worm space saver Mk2

No TRV's

No auto Bypass

sorry if i came across snappy, didnt mean to be

 

[mogget]

Did you sort out the direct connection between your flow and return yet?

 

[bhm1712]

upon a much closer inspection, involving lifting a whole area of floor, the so called direct connection happened not to be one! what i could see from where i was originally looking turned out to be the return from the last upstairs rad which doubled back on the pipework, which from a distance and in the relative darkness appeared to look like a link between the 2 pipes

 

[doitall]

Snappy, nappy more like it

For what it's worth why would a C plan require a by-pass of any type.

Perhaps you have a bathroom radiator connected to the primary pipes, because there's a MV on the return.

 

[mogget]

Glad you got that sorted out bhm

It's quite possible that a radiator without two lockshield valves is in use as a bypass radiator. When I moved into my house the existing system was an open vented Y-plan. Every single radiator was fitted with two wheelhead valves!

 

[bhm1712]

all systems require some sort of bypass, otherwise if somebody turned off all the rads then the boiler would be on overdrive, so would the pump

 

[bhm1712]

i just wonder how it is possible to balance a system if the bypass rad has to be fully open.

 

[doitall]

all systems require some sort of bypass, otherwise if somebody turned off all the rads then the boiler would be on overdrive, so would the pump

Rubbish

Why would someone turn all the rads off and leave the pump on, doing nothing.

The heating is pumped, turn the pump off and you get no heating, simple as that.

The radiator you are talking about, has been connected as a towel rails and may even have been one in a past life.

Turn the pump off and check if the radiator still gets hot, when the HW is on.

 

[bhm1712]

you dont listen to me correctly, in a system with no auto bypass, and all the rads have manual control valves, if for example a child was to turn them all off, the pump would stay on and the boiler would, this could have damaging effects to the pump.

i dont have a towel rail rad connected to the HW.

my system has no bypass valve and all the rads have control wheels so i could turn them all off, leaving the pump pumping to a dead end. other than the vent pipe.

i have read that in this situation where there is no bypass valve, one of the rads usually the rad in the room stat room should be setup as a bypass rad with either 2 LSV or no valves at all so it cannot be turned off easily / at all

i am in the situation where i have no bypass valve and all the rads have manual control valves, so in theory if somebody was to turn them all off i would be in trouble.

 

[doitall]

No, bhm you are the one not listening.

A "C" plan does not need a by-pass, although it was common practice to connect a radiator or towel rail off the primary circuit, it did not act as a by-pass, as it is not in the pumped heating circuit.

The heating is controlled by the pump, when it's running the rads got hot, and sometimes when it wasn't running as well through gravity.

To say a child could turn all the valves off is ridiculous, quite often the valves are so damn stiff even an adult cannot turn them, if you were to install TRVs on all the rads then it would be a different kettle of fish, and irrelevant to your statement anyway.

all systems require some sort of bypass, otherwise if somebody turned off all the rads then the boiler would be on overdrive, so would the pump

i have read that in this situation where there is no bypass valve, one of the rads usually the rad in the room stat room should be setup as a bypass rad with either 2 LSV or no valves at all so it cannot be turned off easily / at all

The regs say that all rads should have TRVs, except the room with the room sat.

The reason is not for a by-pass, but to prevent the rads in that room shutting down before the controlling stat. A by-pass if fitted should be at the beginning of the heating, not the end, or heat is still being pumped into the rooms via the pipework.

Best not to argue, if you don't know, and clearly you don't.

And for the record the cold feed and vent would be on the primary side, Not the heating.

 

[doitall]

what is the definition of a bypass radiator, and is it plumbed in differently than a usual rad? all i know is that it is there as a safeguard for the boiler so there is always a path of flow.

is it possible that on a system with no auto bypass and no rad with 2 lockshields or no valves at all that one of them is still a bypass radiator?

i have been reading that a bypass rad should be fully open either with 2 LSV or no valves at all. if thats the case how can you balance the system properly?

Yes, they may have connected a rad as a by-pass on an older system.

Yes, they may have connected a rad or towel rail, to the primary circuit to get hot when the HWS was on.

Yes they may have connected a rad as a heat sink, for a solid fuel appliance.

But other than the later none are essential, for a "C" plan.