Triton Thames luke warm in winter

[Probe]

Hi,

I'm experiencing a big drop in max water temperature in my shower which seems to reflect the ambient temperature, i.e. it's nice and hot in summer months but drops to luke warm in winter.

The shower is an exposed Triton Thames concentric mixer shower, mains pressure fed. The hot water is supplied via a Greenstar condensing boiler sited in the garage, both are about 5 years old. All pipes are well lagged.

The hot feed pipe feels perfectly hot, almost too hot to touch, and the taps produce good hot water.
I've even tried reducing the pressure on the cold supply to the shower (via a key value) but it seems to make little difference. Could it be something as simple as the fact that the temperature of the cold water supply is that much colder at this time of year?

We live in a very hard water area (Chichester, W.Deleted) so maybe that could have some bearing if mixer values are prone to limescale?

[plumbbob]

Could it be something as simple as the fact that the temperature of the cold water supply is that much colder at this time of year?

If the Thames shower was electric then I would definitely say this is what the cause is but as it isn't, something else is going on.

First of all, can I say that in the winter months, people feel the cold so need the water temperature higher just to have a comfortable shower. It also has to be taken in to account that the air temperature in the bathroom will be lower in the winter and that alone will cause the water leaving the shower head to cool faster giving the impression of a lower performance. Can you be sure this isn't the explanation?

Discounting the above, if this problem has not been experienced in past winters it may be the thermostatic cartridge is beginning to fail. I wonder if the flow limiters have been fitted.

Incidentally, reducing the cold flow won't alter the temperature as the thermostat will just reduce the hot flow accordingly to balance the temperature to what it was before.

[Probe]

Thanks for the reply, plumbbob.

I can certainly see what you're saying about the general lower temperature. However, I'm sure that in the past it's just been a case that it take a little longer for the shower head to get warmed by the water, the nett result was still that the shower prouced a pleasently hot output.

I don't think I remember seeing any flow restrictors when I removed the elbow filters, but perhaps worth me verifying. Your suggestion that the thermostatic cartridge is playing up sounds a more plausible one (and sadly the most costly!).

I'm such a damn amature, It just goes to show that a little knowledge can be dangerous! I'll de-restrict the cold feed.

Cheers

[plumbbob]

Thinking about it, there is one other thing we may have overlooked and that is a partially blocked hot inlet filter. If you check in the elbows next to the flow restrictors there are wire strainer filters. Sometimes these can become choked with limescale or other particles. Although I cannot guarantee it, this might limit the maximum temperature the shower can achieve. However, I would expect blocked filters to effect the flow of water.

Incidentally, I assume you are saying the shower now cannot reach the desired temperature even at the maximum setting? Have you considered altering the maximum so it can be turned higher? The maximum setting is usually pre-set at the factory, but the stop that can be moved by the installer.

[Probe]

I'll double check the filter on the hot feed but the last time I checked it was clear.

Yes, the adjustment is on max. The temperature of the shower doesn't change from a setting of 6 O'clock back to 1 O'clock (max).

I'm pretty sure you identified the issue when you suggested the thermastatic cartridge.