Our hot water is not so hot. Previously we could run a full bath of hot water with no problem. Now, after about 30 seconds, the water begins to run tepid.
We have an indirect water system with gas central heating run by an Ideal Classic RS250 boiler. The central heating still works.
The set up of the hot water cylinder is that instead of a cylinder thermostat, there is a TRV on the pipe going into the heat exchanger coil (wired to a detector on the outside of the cylinder). The flow pipe from the boiler and return pipe are on the top of the cylinder rather than the side. The pipe going into the coil is boiling hot so it should be heating all the water in the cylinder.
I can't find a three-way (or even two-way) valve anywhere so I'm assuming we don't have one. Basically the timer in the airing cupboard has to be on to give us hot water and central heating. It's one of those simple dial jobbies with trip switches which have "on until B", "off until C", "on until D" and "off until A" If we don't want CH then we just turn off all the radiator TRVs.
Until the problem happened we had the thermostat on the boiler set to 3 (the recommended summer setting - I'd forgotten to increase it for the winter) and the TRV on the hot water cylinder set to 6 or 7. The actions I've done since are to increase the boiler thermostat to 5. I've bled all the radiators as well as a couple of bleed valves on the pipes going into and out of the hot water cylinder coil. There is a slight drip from the hot tap in the kitchen which needs fixing but I don't think this has any bearing on the problem as it didn't start at the same time as the tepid water.
An amateur plumber friend suggested there may be an airlock in the coil and suggested turning off all radiators, turning the hot water cylinder TRV to max and leaving it an hour or two - he thought this would blast the air lock out. Unfortunately, it didn't work. Other than the initial lot of hot water being hotter than before, it soon settled down into its tepid state. My friend also suggested that it may be due to a failed thermostat inside the hot water cylinder, although I wasn't aware there was such a thing. Maybe I misunderstood him and he meant the thermostat on the outside of the cylinder.
Does anyone have any suggestions?
We have an indirect water system with gas central heating run by an Ideal Classic RS250 boiler. The central heating still works.
The set up of the hot water cylinder is that instead of a cylinder thermostat, there is a TRV on the pipe going into the heat exchanger coil (wired to a detector on the outside of the cylinder). The flow pipe from the boiler and return pipe are on the top of the cylinder rather than the side. The pipe going into the coil is boiling hot so it should be heating all the water in the cylinder.
I can't find a three-way (or even two-way) valve anywhere so I'm assuming we don't have one. Basically the timer in the airing cupboard has to be on to give us hot water and central heating. It's one of those simple dial jobbies with trip switches which have "on until B", "off until C", "on until D" and "off until A" If we don't want CH then we just turn off all the radiator TRVs.
Until the problem happened we had the thermostat on the boiler set to 3 (the recommended summer setting - I'd forgotten to increase it for the winter) and the TRV on the hot water cylinder set to 6 or 7. The actions I've done since are to increase the boiler thermostat to 5. I've bled all the radiators as well as a couple of bleed valves on the pipes going into and out of the hot water cylinder coil. There is a slight drip from the hot tap in the kitchen which needs fixing but I don't think this has any bearing on the problem as it didn't start at the same time as the tepid water.
An amateur plumber friend suggested there may be an airlock in the coil and suggested turning off all radiators, turning the hot water cylinder TRV to max and leaving it an hour or two - he thought this would blast the air lock out. Unfortunately, it didn't work. Other than the initial lot of hot water being hotter than before, it soon settled down into its tepid state. My friend also suggested that it may be due to a failed thermostat inside the hot water cylinder, although I wasn't aware there was such a thing. Maybe I misunderstood him and he meant the thermostat on the outside of the cylinder.
Does anyone have any suggestions?
