Hot water in bath - installer says not his problem

John_Jizzle

my boiler is an Ideal 24 Combi.

Hasbeen

Older conventional boilers heated hot water tank which fed bath through 22mm pipe.

New Combi boilers require hot feed to bath at 15mm to restrict flow.

If using existing 22mm pipework to fit new bath the bath tap will draw the water through the combi too quick.

Some plumbers renew all or portion of 22mm pipe with 15mm or incorporate restrictor.

Pennywise

Sounds very similar to a problem we had if the hot flow to the bath fluctuates. We had the installer back several times, who denied any problems and blamed the boiler. Eventually got the boiler engineer called out who diagnosed the problem within a couple of minutes. Low gas pressure!

If you call on the combi for too much hot water, and the gas pressure to your home is too low, it will cut out. Ours worked fine for a sink tap on say half power when the central heating was on, as the boiler was already running hot so could cope with the call for hot water. But if the boiler was cold or you had a couple of taps calling for hot water (or the bath), it would be constantly cutting out and resetting itself, so would run cold, then warm up slightly, then go back to cold again. The installers just wouldn't accept there was a problem and were blaming us for being unreasonable with our need for a hot bath - telling us we were just used to having a hot cylinder etc - whenever they came out, the c/h had been on so the boiler looked as if it was working properly! It wasn't until one day, we deliberately kept the C/h turned off for a few hours before we insisted they come out and they then saw our problem and agreed to call out the boiler engineers.

The boiler engineer was none too happy and told us it's a very common problem when installing a combi as the plumber tends not to check the gas pressure! Worst still was that he turned off our house gas supply as he deemed it dangerous due to being low pressure, so we were without gas for a few days whilst the gas supply to our house was upgraded!

Our boiler needs gas pressure of 20, and normal gas pressure is apparently 19-21, but our house supply was only 15! Our plumber tried to claim he'd checked it and that it was probably just a matter of supply/demand, but the boiler engineer said that normal use would never fluctuate by so much whatever time of day. When we checked the installation checklists, it was very damning that the plumber had left most of it blank, including the gas pressure which the paperwork showed he should have checked and recorded!

zaax

Gas pressure might be the problem, as said above. A combi uses gas quicker than a older boiler, the installer should have replaced the gas pipe.

bris

John_Jizzle wrote: »

my boiler is an Ideal 24 Combi.

It only puts out at maximum 9.9lpm (maximum is in ideal conditions in the summer when the water temp is at it's highest) , usually much less. This is your problem. It's a small boiler when it comes to output but you need to be realistic and accept the fact that all you need to do is not open the bath tap fully and let the boiler catch up with the water going through it.


Your boiler is suited to a two bedroom or even a small 3 bed property but it has limitations of hot water output.

m0bov

Who have you paid for the work? What does the contract say and how did you pay for it? Receipt?

Blackbeard_of_Perranporth

Mixer taps have the be taken off the same feed or pressure. If you gave a tank, then the company led water feed has to be taken from the header rank, so it's the same pressure as the hot water. If the hot water comes off the tank, and cold water from the rising main, then the pressure of the rising main will cause the cold to take most of the flow, hence reducing the hot water temperature.

If you have a condensing boiler, that delivers hot water on demand, then the boiler is not capable of delivering the hot water to the bath. Another reason not to believe the hype of using so called green condensing boilers.

And as I live in Gloucestershire, those who had these system in 2007 and the floods, soon found they had no stored water available.

On reading further, combo boiler! Oh dear, never mind. They're just like the old geyser man had. If you wanted a bath, wait til a sunny day in June and a week to fill the tub!