This question is regarding Sirrus Antique 1500 Series Brass/Gold Cartridge Assembly (no thermostat)

Problems with water temperature (not hot enough)

Hi, I wonder if you can help me with a problem I have with the temperature after fitting a Sirrus 1500 Antique Cartridge GOLD (No Thermostat) SK1500-7GP recently bought from you and fitting a subsequent compatible thermostat (again recently purchased from you). We had been having frequent problems with the shower over the bath in the bathroom for several months with the temperature sometimes only lukewarm and other occasions adequately hot. I contacted your company asking for advice as though the shower was around 16 years old it contained a relatively new cartridge that I had purchased from you around Sept/Oct 2014. Trying to increase the temperature setting by turning the adjusting screw anticlockwise made no difference and the advice given was that it could be a faulty thermostat or shuttle. I ruled out the shuttle as one was provided as part of the piston that came with the cartridge purchased in 2014. Recently the ensuite was completely refurbished and I retained the shower that was removed as it was identical to that in the bathroom – in case I needed “spares” in the future. So I used the spare thermostat to replace the one in the bathroom shower. Here it gets complicated but briefly the replacement thermostat made no difference to the variance in temperature and ended up with a reduced water flow (!) – went back to square one and removed/replaced the cartridge to try and correct the slow water flow but then couldn’t turn the shower off! Called out an emergency plumber (from Dyno) who was next to useless (e.g. asked us which way the thermostat went in!), reduced the water flow to an annoying constant dribble by applying loads of plumber’s tape and also stuffed the cartridge so it was permanently jammed in the closed position even after removing the plumber’s tape. Decided to bite the bullet and buy a new cartridge but as the water temperature was now permanently lukewarm even after fitting I purchased a new thermostat a couple of days later. I am now in the positon where water flow is good and temperature improved but still not relaxingly hot (even with the adjusting screw fully set anticlockwise). What we’ve noticed though is that when the cold water tap is turned on in the bathroom sink while the shower is running the water goes very hot, so I turned mains water pressure down low and though improved temperature very slightly was still only a hot temperature when sink cold water tap on again. What can the problem be as basically apart from the housing in which to fit the cartridge etc I have a system with totally new parts – cartridge, piston and thermostat. If it helps, our cold water supply is direct mains fed and our water heater is an unvented type which is supplied directly from the mains supply and therefore does not need separate feed cisterns or vent pipes. The make/model is a Heatrae Sadia Megaflow, model CL210 which is indirectly heated from our boiler but has an immersion heater in case the boiler fails. Could it be that the Sirrus 1500 Antique Cartridge GOLD (No Thermostat) SK1500-7GP is incompatible with our water heater? There has been absolutely no problem with the new shower fitted in the ensuite since it was installed in December, also all sink and bath taps are hot so no problem with the Megaflow. Regards Colin
Asked 8 years ago by Colin
Regarding the temperature fluctuation or cool running, it could be a faulty cartridge. However to check this if you have the shower fed from a combi boiler, see if you can get hold of the hot supply pipe before it enters the shower or perhaps as it leaves the boiler.


If when holding this pipe the temperature fluctuates or goes cool, then the problem is not with the shower but more likely with the boiler, as the shower can only deliver what the boiler sends to it.

Disregard the temperature at the taps as they have a different flow rate.

If you have hot water arriving at the valve and it still isn't hot enough then that suggests that the pressure in the cold is overcoming the pressure in the hot this may be resolved by fitting a flow restrictor in the cold supply.

Answered 8 years ago by Anonymous

Thanks George,

When touching the hot inlet elbow pipe of the shower valve assembly where it connects to the hot water supply pipe I can only place my hand on it for a few moments as it is so hot. To me it indicates that the system boiler is working fine and the valve should also be fine as I only bought it from the Shower Doctor a couple of weeks back. I think your suggestion regarding the flow pressure is very likely as I have now turned the mains pressure down so that the mains stop tap is barely open (even at that setting I am still getting good water flow from the taps) and now the temperature of the shower has risen considerably, meaning we can now have a nice hot shower.

In my original message I related how initially I couldn’t turn the water flow off from the shower and a plumber came out and couldn’t fix the problem but reduced the flow to an annoying constant dribble and stuffed a cartridge that I had only bought from you around September 2014. I also mentioned in my original message that I had a spare, identical shower that I kept to cannibalise for parts if/when required. In an attempt to stop the constant dribble I replaced the housing (i.e. where the valve and piston fits into from the faulty shower with the one from the spare. Could it be that there are different flow limiters between the one I swapped and the spare? I have the original installation manual for this shower model – our house was a new build in 1999 and the showers were installed by the plumber contracted by the house builder. The shower from which the spare one came always used to heat up a lot quicker than the one over the bath and therefore I assume this means it was closer to the water heater supply (i.e. the unvented Megaflo system). I have attached a photo of the page of the installation manual where it provides site installation details and mentions what flow limiters to install depending on distance of the hot water supply in 3 scenarios (shown as a), b) and c)) – below c) there is specific instruction for an Unvented System stating the limiters that should be fitted for the hot and cold supply. I’ve assumed this instruction to be the case regardless of the distance from the hot water supply (and if so would mean that both shower housings have the same limiters installed), but am I correct in this assumption? Can you advise on whether these hot and cold limiters are connected when an unvented system provides the hot supply regardless of distance?

Regards
Colin

Answered 8 years ago by Colin Gadd

It sounds like the thermostat is the wrong way around or the shuttle is sticking in the body of the shower.

You will need to check these.

Answered 8 years ago by Anonymous

You appear to be answering my initial query, not the follow-up one (concerning flow limiters and Unvented systems) therefore please could you answer my follow-up query. In answer to your response anyway - the thermostat is the right way around and the shuttle is not sticking.

Thanks
Colin

Answered 8 years ago by Colin Gadd

Can't advise on whether the limiters are there or not, as you may gather from the "instructions" fitting limiters is rather a black art.

From your previous posts you need to find out what limiters are fitted if any, then I would start by removing any in the hot supply and fitting the smallest one you have to the cold supply.

Answered 8 years ago by Anonymous

View Product and Order Online:

Do you require any further help with Tap or Shower Cartridges?

Please click the following link if you would like to see other answers or ask a question regarding the Sirrus Antique 1500 Series Brass/Gold Cartridge Assembly (no thermostat)

If you've landed here and this question is not about your specific product, please take a look at these similar items on our Bristan Cartridges page. Alternatively, if you're looking for any other brands you should view our full range of Cartridges.

If you would like to buy this cartridge or look others from the same brand, please view our Replacement Bristan Cartridges (All)

For any other support request please get in touch.