new combi boiler, water system and mixer shower but shower not very powerful at all..

kateharv

We have recently had our old cylinder heater and boiler replaced with a 30kw glow-worm combi boiler. This has been fitted in our old cylinder cupboard behind our bath and we have had a new Architeckt thermostatic mixer shower fitted to run off this. Before these were fitted we also had a new water system fitted by the water company as we used to be on a shared system.

Our installer had the boiler and shower fitted by Tuesday evening and the shower pressure was fine, although the shower didn’t get very hot even with the temperature knob completely on. He needed to come back on Wednesday to fit the thermostat etc and I mentioned the heat issue to him.

When we came home from work yesterday, the heat of the shower is better but the power has gone a bit weird. When you turn the shower on the power is fine but then it drops significantly almost straight away. I'm not sure if the plumber has done anything to make the shower hotter and therefore the pressure lower?

We noticed the pressure on the display on the boiler was 0.9bar and it says in the manual if it’s less than 1.0bar to add pressure. So we did this and the pressure is now at 2.4bar but the shower is not working any better.

I was under the impression that if we had a new water system, new combi boiler and new shower fitted we would have a pretty good shower!

I was wondering if anyone had any idea what the problem might be? I don’t really want to have to get my plumber back out if it’s a relatively simple thing to fix…

The shower we have is still under warranty and I think we should be able to get our money back if people think this is the problem.

If so, what mixer shower would people suggest that can run off a combi boiler and give good temperature and be quite powerful that won't break the bank?

Sorry for the long post, thanks for your advice in advance!

Kate

djheath

Firstly, that pressure gauge on the boiler is not for your water system, it is for your central heating! It should be at around 1 to 1.5 bar when the central heating is cold. When the central heating is on, it will rise to about 2bar. If it gets to 3 bar then there is an emergency valve which will trip and vent hot water outside the house. If you have increased the pressure of the boiler with the boiler cold to 2.4 bar then you will need to drain some water off the central heating system until the gauge reads 1- 1.5 bar. this is very important!! Use a bleed valve on a radiator (might take you a while), or drain using a drain valve on the bottom of a radiator. I wouldn't operate the central heating with the pressure set at 2.4bar when cold until you reduce the pressure.

Now, your shower could be a number of things. The make of shower, the shower head pipe size, the route the pipes take to get to the shower, etc etc.

You need to measure the flow rate of water in another room (kitchen sink) and do the same at the shower head and see if there is a large difference. I am not hugely oh fait with what the results would be but others should help with this, and I wouldn't want to give you wrong guidance. Basically you're looking to find the point where the water pressure is low - it could be from the supply from the pipe outside, it could be the stop !!!! reducing flow, it could be the boiler reducing the flow, it could be the shower, it could be a bit of crap in the pipe, etc etc. It may take a while, but eliminating bits as you go should sort out the problem.

markleedsuk

Sounds to me as if there is something blocking the outlet to the shower, depending on the mixing valve you have, some come with rubber seals that have a filter as part of them. Most likely is that there is some debis blocking the outlet on the hot/cold or both, the plumber probably did not fully flush the system (hot and cold pipework) and either solder or flux etc is blocking the outlet so should come and fix free of charge. Previous post is correct you need max 1.5 bar on the guage when heating is cold, and heating and hot water are 2 different circuits. The plumber should have told you how, why and when to top up the boiler. Dont worry that its something you have done, get the plumber back, you paid for a system that works properly and currently is doesnt, so tell him to come back and resolve the issues, unless you have low water pressure to your property (at your kitchen sink on the cold tap) the installation is the problem.