DIY Doctor UK DIY Forums

hi sorry if this question has been posted before, i have been through but cant find the answers.
i am wanting to fit a wall mounted power shower and am unsure if the type of cyclinder i have is suitable . i live in a flat so the cylinder has the cold water tank sat directly on top of the hot cylinder and this all sits on a stand 3' high . the only thing that is drawn form the cold tank is the hot tank ( one copper pipe from bottom of cold to the bottom of the hot tanks ) and kitchen and toilet are all taken direct from the mains as is the washing machine . the instructions state that there should be 3" (75mm ) between the bottom of the cold tank and the top of the shower unit and the cold tank must be a minimum of 25 ltr and feeds must be equall ( hot / cold feed from tank )so my system meets the requirements and as all other cold water is from the mains i should be ok . but i have been told my cylinder is no use as there is not enough head of water and it will not fill up quick enough. can anyone advise if i will be ok to fit this shower. ?
thanks

you haven't said what size your hot water cylinder is, thats the critical thing here. power showers are pumped and therefore uses the stored hot water in the tank pretty quickly. check the specification for your shower with regard to minimum size of hot tank (it may not specify or require a minimum - so long as the CW tank can replenish quickly enough it just means that you will be having a cold shower after 2 minutes)

also the hot and cold feeds to the shower will both have to be pumped at the same rate - you cannot pump the main or have your main going directly into the shower as you will get a different flow rate between the hot and cold.

so the cold will have to be pumped from the CW tank feeding the cylinder as well - can the tank handle feeding a pump and replenishing the cylinder simultaneously?

so the answer to your question is yes, in theory at least you can have a power shower - if, as you say, your CW tank meets the minimum requirement (although to me 25L seems a bit small if you are asking it to keep on top of demand for both pumped supplies - but if thats what the manufacturer states then it must be ok) but the size of your hot water cylinder will mean that you will only be able to have very quick showers before you run out of hot water and it starts to run cold. personally if i were you i'd go with electric. its not ideal but its a compromise that many flat-dwellers unfortunately have to make.

hi thanks for the reply , my hot tank is 115 ltrs i think , there is nothing on it to say . but i can say that the mains feed comes in at a very good pressure with no drop eveb if say the washing machine and electric shower are on . the manula says that a 25 ltr cold storage is sufficiant unless there are other demands on it and as mine only feeds the hot tank once fitted the only thing drawing from the tank would be the hot tank and cold feed both going to the shower . the reason for my question to start is i will have to run a pipe to feed the cold side of the shower and this means lifting floor boards wich i didnt want to do if someone could spot something obvious i was missing
thanks again for your reply

The answer to your question is NO, as the manufacturer stats supplies must be equal they are NOT