Water going Hot and Cold constantly.

[GordonInglis]

I have a Modena combi boiler, which was in house when moved there (2 years old). There are a number of problems I am experiencing with this boiler being:-

(1) When having a shower (Power Shower), the water goes hot and cold constantly throughout. This is very annoying. At first I thought this was a problem with the thermostat in the shower, but the bath has started doing this as well.

(2) The water pressure from the tap in the bath is very low, 20-30 minutes to run a bath. All other taps are fine.

(3) The boiler makes a loud boom noise every time it lights. This doesn't bother me, but thought it may be relevant. The pressure seems to sit at about 1.3 bars.

I am not very clued up on CH problems, but if anybody had any suggestions as to what this is (especially point 1) I would be very grateful. Is it a possbility all these things are related?

Thanks.

 

[ChrisR]

Measure the flow rate at showering temperature. Should be about 9.5 litres a minute. If it's slower then the flow problems are sludge in the heat exchanger, probably. Ingnition unrelated, probably a spark gap etc needs servicing.