New Thermostatic Shower Valve?

[Richard10002]

Despite "draining" the system, there was some frozen water in some of the pipes yesterday afternoon and, once the water in the shower valve defrosted, the shower started running, and wouldn't shut off.

 

Removed it, capped the pipes, and all is good.

 

However, I've decided to replace the shower valve, and wonder if anyone can suggest a replacement which is a fair compromise between quality and price?

 

Given the range of prices, I'm wondering what you get for £199.99+ that you don't get for £39.99.

 

It's a bar type thermostatic valve, with inlets at 15mm centres, (I think/hope the inlets are a standard size, so I can use the existing wall mounting).

Edited December 16, 2022 by Richard10002

[GUMPY]

I have one of these on the boat and two at home, cant fault them.

https://www.amazon.co.uk/Bristan-MINI2-TS1203-EH-Commercial/dp/B077J338QB/ref=asc_df_B077J338QB/?

 

[MtB]

18 minutes ago, Richard10002 said:

Given the range of prices, I'm wondering what you get for £199.99+ that you don't get for £39.99.

 

Instructions written in proper English, a technical support phone line, and spare parts availability directly from a UK based network or organisation. Usually.

[Chewbacka]

For home and the boat I buy whatever is reasonably priced in screwfix.

something like this

https://www.screwfix.com/p/triton-pirlo-exposed-thermostatic-bar-mixer-shower-valve-fixed-chrome/551gf#_=p

[Sea Dog]

Why thermostatic? The complexity inside makes them far more delicate than a simple mixer. Much cheaper too. On the boat anyone aboard can tell the  shower is running and hence leave the other taps alone. Keep it simple.

[MtB]

1 minute ago, Sea Dog said:

Why thermostatic? The complexity inside makes them far more delicate than a simple mixer. Much cheaper too. On the boat anyone aboard can tell the  shower is running and hence leave the other taps alone. Keep it simple.

 

I've found thermostatic works much better on boats for a couple of reasons.

 

1) When the hot water source is a Morco. Morcos can vary a bit in temp while they are running and a thermostatic cancels this out while you are showering, so no repeated fiddling with the temp control.

 

2) With most manual and some thermostics, you lose the shower temp setting you arrived at when you turn it off.  With the Triton thermostatic bar mixer someone just linked to above, the temp control is separate from the on/off so when you turn it back on next year when you need another shower, it is already pre-set to the right temp. 

[Chewbacka]

If the ice bust the cast metal body then it needs replacing, but if it’s only the 1/4 turn ceramic valve that was damaged it can easily and cheaply be replaced.

[GUMPY]

14 hours ago, Richard10002 said:

 

It's a bar type thermostatic valve, with inlets at 15mm centres, (I think/hope the inlets are a standard size, so I can use the existing wall mounting).

Assume you mean 150mm centres!

15mm is a bit close.

[blackrose]

1 hour ago, Sea Dog said:

Why thermostatic? The complexity inside makes them far more delicate than a simple mixer. Much cheaper too. On the boat anyone aboard can tell the  shower is running and hence leave the other taps alone. Keep it simple.

 

I tend to agree. Having a simple mixer rather than a complex thermostatic shower mixer would make more sense. I have to take my bristan unit apart and soak it in vinegar annually to make it work properly.  There are just too many little parts and it seems overly complex for what it does. However I don't think I've ever found a simple shower mixer valve - at least not one that would easily replace my thermostatic unit.

 

I'm not sure I understand your second point about anyone being able to tell the shower is running. Why wouldn't they be able to tell with a thermostatic shower mixer?

 

3 minutes ago, Loddon said:

Assume you mean 150mm centres!

15mm is a bit close.

 

Yes it must be 15cm like mine.

Edited December 17, 2022 by blackrose

[Alan de Enfield]

36 minutes ago, blackrose said:

I tend to agree. Having a simple mixer rather than a complex thermostatic shower mixer would make more sense. I have to take my bristan unit apart and soak it in vinegar annually to make it work properly.  There are just too many little parts and it seems overly complex for what it does. However I don't think I've ever found a simple shower mixer valve - at least not one that would easily replace my thermostatic unit.

 

On ours we have an on / flow / off  knob and then a temperature dial around the outside - is this a thermostatic, or not ?

 

The temperature dial goes up to 'quite hot' but if you want more you depress the red button and can continue increasing the temperature. Our Cauliflower is normally at 85°C - 90°C

 

 

Edited December 17, 2022 by Alan de Enfield

[Sea Dog]

1 hour ago, MtB said:

 

2) With most manual and some thermostics, you lose the shower temp setting you arrived at when you turn it off.  With the Triton thermostatic bar mixer someone just linked to above, the temp control is separate from the on/off so when you turn it back on next year when you need another shower, it is already pre-set to the right temp. 

I hesitate to diverge from the knowledge of a pukka heating engineer, but my non thermostatic boat shower mixer is left/right for temp, in/out for flow. It rarely needs any temp adjustment and then only marginal if the tank has cooled. Once running it stays true.

I appreciate your points, and wouldn't have anything but my thermostatic mixers at home for just those reasons, but personally I'd still keep it simple on t'boat. Probably more of a pertinent point for those of us who have to leave our boats for a period when it's freezing, hence the icy death of the OP's thermostatic mixer.

[Richard10002]

1 hour ago, Sea Dog said:

Why thermostatic? The complexity inside makes them far more delicate than a simple mixer. Much cheaper too. On the boat anyone aboard can tell the  shower is running and hence leave the other taps alone. Keep it simple.

1) When we bought the boat it had a simple mixer and, no matter what I did with the taps, the temperature varied from too hot to too cold several times during a shower - really irritating. I had a thermostatic shower valve in the car, so fitted it and all was good for a decade  

 

2) 15cm is correct 

 

3) I'll take it apart and see if the problem is obvious. 

[Ex Brummie]

If I lived full time on the boat then maybe a thermostatic, like at home, would be my choice, but for the boat I fitted one of these which is frost proof and easily set.

https://www.screwfix.com/p/swirl-exposed-shower-valve-fixed-chrome/206PG?tc=DA4&ds_kid=92700046986170840&ds_rl=1241687&ds_rl=1245250&ds_rl=1245725&ds_rl=1245250&gclid=CjwKCAiA7vWcB.

This works quite happily with a Morco and can be adjusted quicker than a thermostatic will react to relatively low throughputs..

[Sea Dog]

55 minutes ago, blackrose said:

I'm not sure I understand your second point about anyone being able to tell the shower is running. Why wouldn't they be able to tell with a thermostatic shower mixer?

My point is that, with a manual mixer, if someone turns on a tap elsewhere your shower temperature quickly enters the "Ooh! zone".  In the smaller space of a boat, and with a fresh water pump and gulper doing their thing, no-one is likely to accidentally operate other taps.  No issue with that for a thermostatic valve of course.

[pete.i]

I had a bar thermostatic shower in my old house that lasted ten years before we moved. It was still okay when we moved out, that was a 39 quid jobby off Ebay. I also fitted one to my last boat, which I have now sold. That had only been in a year or so but was still working when I sold the boat. The only difference I can see between the expensive ones and the cheap ones is that the expensive ones have a known maker's name on them. They are all made in China. Those exposed shower mixer valves shown should fit but they are not bar mixers.

[rusty69]

It's not really related to the thread title (but when did that ever stop me), however last year I fitted a thermostatic mixing valve to the calorifier to prevent scolding at the kitchen taps and bathroom mixer. I didn't want to add a thermostatic valve at the bath mixer in case the Paloma didn't play nice with it, but it seems that from other comments that may have been unfounded.

[Tracy D'arth]

58 minutes ago, Alan de Enfield said:

 

On ours we have an on / flow / off  knob and then a temperature dial around the outside - is this a thermostatic, or not ?

 

The temperature dial goes up to 'quite hot' but if you want more you depress the red button and can continue increasing the temperature. Our Cauliflower is normally at 85°C - 90°C

 

 

Its a thermostatic Mira and a very good valve. Will rarely suffer from scaling they were designed for London hard as bricks water.

21 minutes ago, pete.i said:

I had a bar thermostatic shower in my old house that lasted ten years before we moved. It was still okay when we moved out, that was a 39 quid jobby off Ebay. I also fitted one to my last boat, which I have now sold. That had only been in a year or so but was still working when I sold the boat. The only difference I can see between the expensive ones and the cheap ones is that the expensive ones have a known maker's name on them. They are all made in China. Those exposed shower mixer valves shown should fit but they are not bar mixers.

They vary a lot in quality. The better ones like Grohe are all brass insides, the cheapies like Triton are plastic valves inside.

Matters little if you let them freeze full of water, they will all break.

I would not have a non thermostatic shower for safety reasons no matter how the water was heated.

[blackrose]

Following reading this thread I've found a manual shower mixer that fits and replaced my thermostatic valve.

 

It's so much better. It just gives you the temperature that you want. My old Bristan thermostatic valve used to overcompensate and add too much cold water so you never got a really hot shower unless the water was really hot. I'd adjusted it many times but it never worked that well. And on the rare occasions in summer you wanted a cold shower it wouldn't do that either, going cold for a second before adding hot water.

 

Added to that it needed taking apart annually and soaking in vinegar to descale all the parts.

 

I know there's the risk of scalding with the manual mixer if you've run the engine, but I have a TMV on the calorifier's hot water outlet that I can either use or bypass so I'll just have to make sure I use it if I've run the engine 

Edited December 19, 2022 by blackrose

[nicknorman]

On 17/12/2022 at 09:06, Sea Dog said:

Why thermostatic? The complexity inside makes them far more delicate than a simple mixer. Much cheaper too. On the boat anyone aboard can tell the  shower is running and hence leave the other taps alone. Keep it simple.

You’ve obviously never had the in-laws staying! Or a cycling water pump. Having gone from a boat without a thermostatic mixer, to one with, I would never go back! Especially considering the scalding potential from hot water from an engine-heated calorifier.

[nicknorman]

On 17/12/2022 at 11:13, rusty69 said:

… to prevent scolding at the kitchen taps and bathroom mixer.

You have talking taps? I must get one. Or do you mean the scolding was from the Mrs complaining you’d missed a bit during the washing up?

[Sea Dog]

3 hours ago, nicknorman said:

You’ve obviously never had the in-laws staying! Or a cycling water pump. Having gone from a boat without a thermostatic mixer, to one with, I would never go back! Especially considering the scalding potential from hot water from an engine-heated calorifier.

Well there's a thermostatic mixer on the hot from the tank, so a level of scald protection is already present. Certainly that's never been an issue for us - are you thinking a duffer might set it at full hot and get in without bothering to put a hand under first? Sadly, my in-laws won't be joining us, but when they were alive I can't say I experienced any shower based snag. The cycling water pump I don't understand - I'm not saying it's not a potential problem - but it's again not something I've experienced with a non thermostatic shower.  What's the issue? Partially opened valve? Operator error?

[nicknorman]

37 minutes ago, Sea Dog said:

Well there's a thermostatic mixer on the hot from the tank, so a level of scald protection is already present. Certainly that's never been an issue for us - are you thinking a duffer might set it at full hot and get in without bothering to put a hand under first? Sadly, my in-laws won't be joining us, but when they were alive I can't say I experienced any shower based snag. The cycling water pump I don't understand - I'm not saying it's not a potential problem - but it's again not something I've experienced with a non thermostatic shower.  What's the issue? Partially opened valve? Operator error?

 

Obviously if you have a thermostatic mixer on the hot from the tank, there is less of a problem. But then again if you are up for a thermostatic mixer on the tank, why against a thermostatic mixer on the shower?

Cycling water pump thing does tend to modify the ratio of hot flow vs cold flow as the pump pressure cycles. I suppose it is something to do with one pathway being via an nrv (fixed pressure drop) and calorifier, the other being direct. And when you have effectively one flow rate to be shared between hot and cold, very small changes in the openings of the taps has a big effect on the mix. Well, that was what we found with the boat we used to use that didn't have a thermostatic mixer on the shower anyway. It required fine adjustment to get a tolerable temperature and it wasn't stable.

Edited December 20, 2022 by nicknorman

[Sea Dog]

Just now, nicknorman said:

But then again if you are up for a thermostatic mixer on the tank, why against a thermostatic mixer on the shower?

Actually, I'm not - if you recall, the OP's thermostatic shower valve was damaged in the freeze and he wanted to know what difference the wide range in prices of a replacement made. I exhorted the virtue of keeping things simple where possible. A manual shower valve with a pull/push on-off and a left/right temperature control does the job well, is easy to fully drain down, is less vulnerable to freeze damage - and can be a fair bit cheaper. 

[blackrose]

2 hours ago, nicknorman said:

 

Obviously if you have a thermostatic mixer on the hot from the tank, there is less of a problem. But then again if you are up for a thermostatic mixer on the tank, why against a thermostatic mixer on the shower?

 

 

In my case it's because I've had 2 thermostatic shower mixers and neither have really worked properly as I previously described, whereas the TMV on the tank has always been fine 

[Scholar Gypsy]

17 hours ago, blackrose said:

 

In my case it's because I've had 2 thermostatic shower mixers and neither have really worked properly as I previously described, whereas the TMV on the tank has always been fine 

Same for me.  I have a fixed TMV near the calorifier that mixes and hot and cold,  is the right temperature for the washbasin and the shower, and keeps a stable temperature whatever is done elsewhere. The galley sink is connected direct to the hot, good for filling kettles and doing the washing up.