Worcester Highflow 400 boiler...

[HUFCsteve]

Hi there

We have a Highflow 400 boiler which in the few years we've lived here has proven somewhat problematic.

The most pressing problem at the moment is that the hot water is running cold after a few minutes and the boiler is needing to be reset (bit of an issue when you're trying to have a shower as the boiler is in the garage).

The other problem that has recently resurfaced is that the rads are heating up when the water is on. We thought we'd resolved this before when the diverter valve was replaced.

Does anyone have any suggestions as to what the problem is?

Out of interest, what would the likely cost be to replace this boiler with another one?

 

[gremlin16]

The other problem that has recently resurfaced is that the rads are heating up when the water is on. We thought we'd resolved this before when the diverter valve was replaced.

Got called to similar problem with 400.
The water in rads was jet black, so you can imagine what the boiler was full of.
Advised customer to have the system flushed before replacing any parts.

Not being daft told customer to call WB, they built the carp let them try fix it

Any way they replaced diverter valve, boiler worked fine for about a month. Same problem again so WB changed some more parts.

It worked for a few weeks then same problem. After 3rd visit the WB
engineer decided it needed a flush

Boiler has not been right since.

 

[HUFCsteve]

So how much would it cost to have the system flushed?

 

[fatplumber]

So how much would it cost to have the system flushed?

I charge from £250 upwards, depending on what else I'm doing there.

 

[bengasman]

Flushing the system depends on how badly it is blocked and how many rads you have; to get anywhere near a ballpark figure, take amount of rads times £40 - £50 to get it done properly.
Add about £150 to install a magnaclean when job is done.
Whether you keep the existing boiler or replace it, the above needs to be done anyway as the corrosion will kill any boiler, old or new.

 

[ollski]

Problem is the dhw heat exchanger is blocked and it is a pig of a job to change. Flushing these won't help the immediate problem as it will just block the heat exchanger even further although flushing first followed by a heat exchanger replacement usually sorts it.

 

[bengasman]

Would it not work if you connected the flushmachine via a pump adapter? Works a treat on most plate hex boilers.