DIY Doctor

New Combi Boiler Affecting Temperature Regulation of one of Showers

Postby Andrea9876 » Mon Aug 15, 2016 2:06 pm

Hi all

Middle aged mother of two with no plumbing knowledge looking for advice.

I recently was lucky enough to qualify for a 'free' boiler upgrade with British Gas. I formerly had an immersion heater/tank system and this was changed to a combi boiler. I have two bathrooms and I was told that the shower in the en suite would be rendered useless by the upgrade.

I spoke to some plumber friends who advised they could either replace the extra shower with an electric one or on realising there was a pump under the bath in the main bathroom, pumping the water to the spare shower, they said they could remove that pump and get the spare shower working.

Anyway, the day the gas fitters came to do the boiler they said I need not worry as they will ensure the shower works and they appeared to get it all connected and running. The pressure to the spare shower remains fantastic but we cannot regulate the temperature of the shower. It is either boiling hot or freezing cold, We cannot get any middle ground at all. The controls are complicated anyway. There are 3 knobs. One controls the flow to the main overhead shower head, one controls the flow to a handheld shower head and a middle one controls the temperature. It is a big square knob (all three are) but this one has a button on it but pressing this does not seem to make any difference.

The shower over the bath in the main bathroom continues to work fine and the temperature can be adjusted just the same with the (I think it's called) thermostatic bar that it has.

We really do require the use of the other shower and wondered if there was an obvious solution (that I could understand in lay terms)?

I can ask my plumber friends but I have found in the past that they have charged me for a lot of exploratory work, so I would like to have some ideas to discuss with them before I get them back.

Does anyone have any thoughts.

Many thanks.

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Simply Build It

Postby lets have a look » Tue Aug 16, 2016 7:08 pm

The pump is now useless ,it used to take cold water from a roof tank and hot water from the hot water cylinder and pump it to the shower,you no longer have this system,
now you have a combi the water is pressurised hence no need for a pump to increase the water pressure,the shower you have now sounds like it's not suitable for a combi,

fit a bath/shower bar type thermostatic tap like your other one, cost about £80 online and you have solved the problem
lets have a look
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Postby Andrea9876 » Tue Aug 16, 2016 8:58 pm

Thank you for that. I was hoping it would be that simple. I am sure the pump was disconnected anyway and know it shouldn't be used with a combi.

I texted my usual plumber today and he suggested it sounded like thermostat problem.

The only issue i can potentially see is damage to tiles due to the fancy design of what is already there but at least I will have a working shower.

Thanks again.
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