Hi - we have a recirculating hot water system with a dedicated return to the water heater. The spigots in the master (2 sinks, tub and shower) are taking a LONG time to get hot. The guest bathroom (next furthest) sink gets hot right away, as do other faucets in the house. I'm at a loss to explain this... could someone help with some advice/clues?

Thanks,
Bob

Was it always like that ?

No. This is a recent development. The pump's running...

Was there any (any) plumbing work done on your house recently ?

Predated this by over a month, early January: in kitchen (about midway between water heater and MBA), stubbed a .5" line in wall that fed the fridge icemaker, replaced with .25" line inside of wall. Early February, replaced backflow preventer to the boiler. Neither of these involved hot water lines...

No cartridges replaced in showers / tubs ?

Check that back flow preventer for proper installation as well as that it functions as it should.

Also, did you have to turn off the pump while any of this work was being done ?

Back to you... Milo

Yes, the pump had power removed for a while, now that I think about it. No cartridges and the BF preventer is installed correctly (about 99% sure of that) and seems to be working.

Is the water heater located between m.b. and k.s. and furthest hall bath. If so best way to run a return line is with a loop. Starting at water heater then looping around the fixtures and back to water heater. Running a straight shot to furthest outlet would delay hot water if branches are 10' away. DID ANY OF BATH ADDED TO HOUSE RECENTLY?

When you say " it takes a long time to get hot" does the water eventually get to the same temperature as before or does it feel hotter/cooler when it reaches max. temperature?

Hi Bob...

Even though you worked only on cold water lines it is very possible that the recirculating hot water line was affected when the cold water was shut down but the circulator wasn't. Here, cold water was shut down while the pump was pulling on the hot water recirc. Line, but no water was being pulled into the recirc. Line because no cold water getting fed into the hot water heater so you end up with AIR in the recirculating hot water line.

My guess here is that recirculating line and pump are AIRLOCKED and the recirc. line needs to be bled of air. Here, hot water would be getting to the closer bath because you use the closer fixtures and other fixtures often enough that hot water is readily available in the regular hot water pipe. With the farthest fixtures at the master bath the recir. Line is needed to make things as they have always been... perhaps.

Are there any union fittings at this recirc. Pump? How about a shutoff on each side of the recirculating pump? If so, you may be able to purge the air by breaking the union(s) or by isolating the shutoffs and bleeding through the caps on the shutoffs (if present). Otherwise, I think you need to get a union or shutoffs (with draincaps) installed at the pump so you can bleed the recirc. Line now and in the future if needed.

That's my thoughts. Questions? Let me know, OK?

Mark

What I meant is instead of being 5 seconds, it is 30-60 seconds instead. It is an example only. Temperature stays the same.

Bingo, Mark! Closed the valves and opened the union. Hot water now coming up to temp as expected. Thanks to all who helped.

Bob

I had a feeling here Bob... ;) Glad to help!

Mark