Legal Disclaimer      Cookie Policy

Updated 01 November 2020   Boiler Services Ltd 2009-2020

Link to Central Heating Problems and Gas Boiler Problems home page

heating and boiler problems  –

Tap water would start hot for a few seconds then would run barely warm. Radiators had been coming on unwanted. We found that the boiler was also firing  when no external demand was present at all and the display showed "d" suggesting that domestic hot water was being supplied.

We removed the actuator from the diverter valve and found that there was very little travel on the push rod of the diverter valve, only about 2mm. We suspected the diverter might be faulty but also suspected the circuit board as the boiler fired with no external demand. We had checked the incoming electrical supply to the boiler and found 230V AC between L3 (permanent live) and Neutral but no voltage between L2 (switched live) and Neutral.

We rang Ideal Tech Services and asked what push rod travel we should expect on the diverter valve but they didn't know. They said they needed to know what the display showed while the boiler was running without being called for. Since it showed a domestic hot water demand "d" they asked us to turn off the cold mains water inlet valve to ensure that no hot water was being supplied. This made no difference and the boiler continued to fire. Ideal Tech Services said this implicated the diverter valve.

We changed the diverter valve assembly which was simple after relieving the heating system pressure (4 Allen bolts with easy access). The boiler worked normally with the new diverter; tap water at the correct temperature and no radiators hot without a heating demand.

For reference, this was the WILO water set diverter valve and the travel on the push rod of the new diverter was about 10mm. We don't know the normal travel on the CP waterset push rod but suspect it will be similar. If we find it we'll publish it here.

Please read our Legal Disclaimer

Ideal Isar HE24 Gas Combination Boiler Faults, Problems and Fault-finding

Ideal Isar HE24 Combi Boiler Fault

Customer reported problems with insufficiently hot tap water

This page is copyright but if you want to link to it directly from your site the hyperlink is:

Back to the top